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   * Copyright (c) 2012, 2015, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
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   * published by the Free Software Foundation.  Oracle designates this
   * particular file as subject to the "Classpath" exception as provided
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   *
   * This code is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   * version 2 for more details (a copy is included in the LICENSE file that
   * accompanied this code).
   *
   * You should have received a copy of the GNU General Public License version
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   *
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  /*
   * This file is available under and governed by the GNU General Public
   * License version 2 only, as published by the Free Software Foundation.
   * However, the following notice accompanied the original version of this
   * file:
   *
   * Copyright (c) 2007-2012, Stephen Colebourne & Michael Nascimento Santos
   *
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *
   *  * Redistributions of source code must retain the above copyright notice,
   *    this list of conditions and the following disclaimer.
   *
   *  * Redistributions in binary form must reproduce the above copyright notice,
   *    this list of conditions and the following disclaimer in the documentation
   *    and/or other materials provided with the distribution.
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   *  * Neither the name of JSR-310 nor the names of its contributors
   *    may be used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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  package java.time;
  
  import java.io.DataOutput;
  import java.io.IOException;
  import java.io.InvalidObjectException;
  import java.io.ObjectInputStream;
  import java.io.Serializable;
  import java.time.format.DateTimeFormatterBuilder;
  import java.time.format.TextStyle;
  import java.time.temporal.TemporalAccessor;
  import java.time.temporal.TemporalField;
  import java.time.temporal.TemporalQueries;
  import java.time.temporal.TemporalQuery;
  import java.time.temporal.UnsupportedTemporalTypeException;
  import java.time.zone.ZoneRules;
  import java.time.zone.ZoneRulesException;
  import java.time.zone.ZoneRulesProvider;
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.Locale;
  import java.util.Map;
  import java.util.Objects;
  import java.util.Set;
  import java.util.TimeZone;
  
  // Android-changed: removed ValueBased paragraph.
  // Android-changed: removed {@link ZoneRulesProvider}.
  
  /**
   * A time-zone ID, such as {@code Europe/Paris}.
   * <p>
   * A {@code ZoneId} is used to identify the rules used to convert between
   * an {@link Instant} and a {@link LocalDateTime}.
   * There are two distinct types of ID:
   * <ul>
   * <li>Fixed offsets - a fully resolved offset from UTC/Greenwich, that uses
   *  the same offset for all local date-times
   * <li>Geographical regions - an area where a specific set of rules for finding
   *  the offset from UTC/Greenwich apply
   * </ul>
   * Most fixed offsets are represented by {@link ZoneOffset}.
   * Calling {@link #normalized()} on any {@code ZoneId} will ensure that a
   * fixed offset ID will be represented as a {@code ZoneOffset}.
   * <p>
   * The actual rules, describing when and how the offset changes, are defined by {@link ZoneRules}.
   * This class is simply an ID used to obtain the underlying rules.
   * This approach is taken because rules are defined by governments and change
   * frequently, whereas the ID is stable.
   * <p>
   * The distinction has other effects. Serializing the {@code ZoneId} will only send
   * the ID, whereas serializing the rules sends the entire data set.
   * Similarly, a comparison of two IDs only examines the ID, whereas
   * a comparison of two rules examines the entire data set.
   *
   * <h3>Time-zone IDs</h3>
   * The ID is unique within the system.
   * There are three types of ID.
   * <p>
   * The simplest type of ID is that from {@code ZoneOffset}.
   * This consists of 'Z' and IDs starting with '+' or '-'.
   * <p>
   * The next type of ID are offset-style IDs with some form of prefix,
   * such as 'GMT+2' or 'UTC+01:00'.
   * The recognised prefixes are 'UTC', 'GMT' and 'UT'.
   * The offset is the suffix and will be normalized during creation.
   * These IDs can be normalized to a {@code ZoneOffset} using {@code normalized()}.
   * <p>
   * The third type of ID are region-based IDs. A region-based ID must be of
   * two or more characters, and not start with 'UTC', 'GMT', 'UT' '+' or '-'.
   * Region-based IDs are defined by configuration.
   * The configuration focuses on providing the lookup from the ID to the
   * underlying {@code ZoneRules}.
   * <p>
   * Time-zone rules are defined by governments and change frequently.
   * There are a number of organizations, known here as groups, that monitor
   * time-zone changes and collate them.
   * The default group is the IANA Time Zone Database (TZDB).
   * Other organizations include IATA (the airline industry body) and Microsoft.
   * <p>
   * Each group defines its own format for the region ID it provides.
   * The TZDB group defines IDs such as 'Europe/London' or 'America/New_York'.
   * TZDB IDs take precedence over other groups.
   * <p>
   * It is strongly recommended that the group name is included in all IDs supplied by
   * groups other than TZDB to avoid conflicts. For example, IATA airline time-zone
   * region IDs are typically the same as the three letter airport code.
   * However, the airport of Utrecht has the code 'UTC', which is obviously a conflict.
   * The recommended format for region IDs from groups other than TZDB is 'group~region'.
   * Thus if IATA data were defined, Utrecht airport would be 'IATA~UTC'.
   *
   * <h3>Serialization</h3>
   * This class can be serialized and stores the string zone ID in the external form.
   * The {@code ZoneOffset} subclass uses a dedicated format that only stores the
   * offset from UTC/Greenwich.
   * <p>
   * A {@code ZoneId} can be deserialized in a Java Runtime where the ID is unknown.
   * For example, if a server-side Java Runtime has been updated with a new zone ID, but
   * the client-side Java Runtime has not been updated. In this case, the {@code ZoneId}
   * object will exist, and can be queried using {@code getId}, {@code equals},
   * {@code hashCode}, {@code toString}, {@code getDisplayName} and {@code normalized}.
   * However, any call to {@code getRules} will fail with {@code ZoneRulesException}.
   * This approach is designed to allow a {@link ZonedDateTime} to be loaded and
   * queried, but not modified, on a Java Runtime with incomplete time-zone information.
   *
   * @implSpec
   * This abstract class has two implementations, both of which are immutable and thread-safe.
   * One implementation models region-based IDs, the other is {@code ZoneOffset} modelling
   * offset-based IDs. This difference is visible in serialization.
   *
   * @since 1.8
   */
  public abstract class ZoneId implements Serializable {
  
      /**
       * A map of zone overrides to enable the short time-zone names to be used.
       * <p>
       * Use of short zone IDs has been deprecated in {@code java.util.TimeZone}.
       * This map allows the IDs to continue to be used via the
       * {@link #of(String, Map)} factory method.
       * <p>
       * This map contains a mapping of the IDs that is in line with TZDB 2005r and
       * later, where 'EST', 'MST' and 'HST' map to IDs which do not include daylight
       * savings.
       * <p>
       * This maps as follows:
       * <ul>
       * <li>EST - -05:00</li>
       * <li>HST - -10:00</li>
       * <li>MST - -07:00</li>
       * <li>ACT - Australia/Darwin</li>
       * <li>AET - Australia/Sydney</li>
       * <li>AGT - America/Argentina/Buenos_Aires</li>
       * <li>ART - Africa/Cairo</li>
       * <li>AST - America/Anchorage</li>
       * <li>BET - America/Sao_Paulo</li>
       * <li>BST - Asia/Dhaka</li>
       * <li>CAT - Africa/Harare</li>
       * <li>CNT - America/St_Johns</li>
       * <li>CST - America/Chicago</li>
       * <li>CTT - Asia/Shanghai</li>
       * <li>EAT - Africa/Addis_Ababa</li>
       * <li>ECT - Europe/Paris</li>
       * <li>IET - America/Indiana/Indianapolis</li>
       * <li>IST - Asia/Kolkata</li>
       * <li>JST - Asia/Tokyo</li>
       * <li>MIT - Pacific/Apia</li>
       * <li>NET - Asia/Yerevan</li>
       * <li>NST - Pacific/Auckland</li>
       * <li>PLT - Asia/Karachi</li>
       * <li>PNT - America/Phoenix</li>
       * <li>PRT - America/Puerto_Rico</li>
       * <li>PST - America/Los_Angeles</li>
       * <li>SST - Pacific/Guadalcanal</li>
       * <li>VST - Asia/Ho_Chi_Minh</li>
       * </ul>
       * The map is unmodifiable.
       */
      public static final Map<String, String> SHORT_IDS;
      static {
          Map<String, String> map = new HashMap<>(64);
          map.put("ACT", "Australia/Darwin");
          map.put("AET", "Australia/Sydney");
          map.put("AGT", "America/Argentina/Buenos_Aires");
          map.put("ART", "Africa/Cairo");
          map.put("AST", "America/Anchorage");
          map.put("BET", "America/Sao_Paulo");
          map.put("BST", "Asia/Dhaka");
          map.put("CAT", "Africa/Harare");
          map.put("CNT", "America/St_Johns");
          map.put("CST", "America/Chicago");
          map.put("CTT", "Asia/Shanghai");
          map.put("EAT", "Africa/Addis_Ababa");
          map.put("ECT", "Europe/Paris");
          map.put("IET", "America/Indiana/Indianapolis");
          map.put("IST", "Asia/Kolkata");
          map.put("JST", "Asia/Tokyo");
          map.put("MIT", "Pacific/Apia");
          map.put("NET", "Asia/Yerevan");
          map.put("NST", "Pacific/Auckland");
          map.put("PLT", "Asia/Karachi");
          map.put("PNT", "America/Phoenix");
          map.put("PRT", "America/Puerto_Rico");
          map.put("PST", "America/Los_Angeles");
          map.put("SST", "Pacific/Guadalcanal");
          map.put("VST", "Asia/Ho_Chi_Minh");
          map.put("EST", "-05:00");
          map.put("MST", "-07:00");
          map.put("HST", "-10:00");
          SHORT_IDS = Collections.unmodifiableMap(map);
      }
      /**
       * Serialization version.
       */
      private static final long serialVersionUID = 8352817235686L;
  
      //-----------------------------------------------------------------------
      /**
       * Gets the system default time-zone.
       * <p>
       * This queries {@link TimeZone#getDefault()} to find the default time-zone
       * and converts it to a {@code ZoneId}. If the system default time-zone is changed,
       * then the result of this method will also change.
       *
       * @return the zone ID, not null
       * @throws DateTimeException if the converted zone ID has an invalid format
       * @throws ZoneRulesException if the converted zone region ID cannot be found
       */
      public static ZoneId systemDefault() {
          return TimeZone.getDefault().toZoneId();
      }
  
      /**
       * Gets the set of available zone IDs.
       * <p>
       * This set includes the string form of all available region-based IDs.
       * Offset-based zone IDs are not included in the returned set.
       * The ID can be passed to {@link #of(String)} to create a {@code ZoneId}.
       * <p>
       * The set of zone IDs can increase over time, although in a typical application
       * the set of IDs is fixed. Each call to this method is thread-safe.
       *
       * @return a modifiable copy of the set of zone IDs, not null
       */
      public static Set<String> getAvailableZoneIds() {
          return ZoneRulesProvider.getAvailableZoneIds();
      }
  
      //-----------------------------------------------------------------------
      /**
       * Obtains an instance of {@code ZoneId} using its ID using a map
       * of aliases to supplement the standard zone IDs.
       * <p>
       * Many users of time-zones use short abbreviations, such as PST for
       * 'Pacific Standard Time' and PDT for 'Pacific Daylight Time'.
       * These abbreviations are not unique, and so cannot be used as IDs.
       * This method allows a map of string to time-zone to be setup and reused
       * within an application.
       *
       * @param zoneId  the time-zone ID, not null
       * @param aliasMap  a map of alias zone IDs (typically abbreviations) to real zone IDs, not null
       * @return the zone ID, not null
       * @throws DateTimeException if the zone ID has an invalid format
       * @throws ZoneRulesException if the zone ID is a region ID that cannot be found
       */
      public static ZoneId of(String zoneId, Map<String, String> aliasMap) {
          Objects.requireNonNull(zoneId, "zoneId");
          Objects.requireNonNull(aliasMap, "aliasMap");
          String id = aliasMap.get(zoneId);
          id = (id != null ? id : zoneId);
          return of(id);
      }
  
      /**
       * Obtains an instance of {@code ZoneId} from an ID ensuring that the
       * ID is valid and available for use.
       * <p>
       * This method parses the ID producing a {@code ZoneId} or {@code ZoneOffset}.
       * A {@code ZoneOffset} is returned if the ID is 'Z', or starts with '+' or '-'.
       * The result will always be a valid ID for which {@link ZoneRules} can be obtained.
       * <p>
       * Parsing matches the zone ID step by step as follows.
       * <ul>
       * <li>If the zone ID equals 'Z', the result is {@code ZoneOffset.UTC}.
       * <li>If the zone ID consists of a single letter, the zone ID is invalid
       *  and {@code DateTimeException} is thrown.
       * <li>If the zone ID starts with '+' or '-', the ID is parsed as a
       *  {@code ZoneOffset} using {@link ZoneOffset#of(String)}.
       * <li>If the zone ID equals 'GMT', 'UTC' or 'UT' then the result is a {@code ZoneId}
       *  with the same ID and rules equivalent to {@code ZoneOffset.UTC}.
       * <li>If the zone ID starts with 'UTC+', 'UTC-', 'GMT+', 'GMT-', 'UT+' or 'UT-'
       *  then the ID is a prefixed offset-based ID. The ID is split in two, with
       *  a two or three letter prefix and a suffix starting with the sign.
       *  The suffix is parsed as a {@link ZoneOffset#of(String) ZoneOffset}.
       *  The result will be a {@code ZoneId} with the specified UTC/GMT/UT prefix
       *  and the normalized offset ID as per {@link ZoneOffset#getId()}.
       *  The rules of the returned {@code ZoneId} will be equivalent to the
       *  parsed {@code ZoneOffset}.
       * <li>All other IDs are parsed as region-based zone IDs. Region IDs must
       *  match the regular expression <code>[A-Za-z][A-Za-z0-9~/._+-]+</code>
       *  otherwise a {@code DateTimeException} is thrown. If the zone ID is not
       *  in the configured set of IDs, {@code ZoneRulesException} is thrown.
       *  The detailed format of the region ID depends on the group supplying the data.
       *  The default set of data is supplied by the IANA Time Zone Database (TZDB).
       *  This has region IDs of the form '{area}/{city}', such as 'Europe/Paris' or 'America/New_York'.
       *  This is compatible with most IDs from {@link TimeZone}.
       * </ul>
       *
       * @param zoneId  the time-zone ID, not null
       * @return the zone ID, not null
       * @throws DateTimeException if the zone ID has an invalid format
       * @throws ZoneRulesException if the zone ID is a region ID that cannot be found
       */
      public static ZoneId of(String zoneId) {
          return of(zoneId, true);
      }
  
      /**
       * Obtains an instance of {@code ZoneId} wrapping an offset.
       * <p>
       * If the prefix is "GMT", "UTC", or "UT" a {@code ZoneId}
       * with the prefix and the non-zero offset is returned.
       * If the prefix is empty {@code ""} the {@code ZoneOffset} is returned.
       *
       * @param prefix  the time-zone ID, not null
       * @param offset  the offset, not null
       * @return the zone ID, not null
       * @throws IllegalArgumentException if the prefix is not one of
       *     "GMT", "UTC", or "UT", or ""
       */
      public static ZoneId ofOffset(String prefix, ZoneOffset offset) {
          Objects.requireNonNull(prefix, "prefix");
          Objects.requireNonNull(offset, "offset");
          if (prefix.length() == 0) {
              return offset;
          }
  
          if (!prefix.equals("GMT") && !prefix.equals("UTC") && !prefix.equals("UT")) {
               throw new IllegalArgumentException("prefix should be GMT, UTC or UT, is: " + prefix);
          }
  
          if (offset.getTotalSeconds() != 0) {
              prefix = prefix.concat(offset.getId());
          }
          return new ZoneRegion(prefix, offset.getRules());
      }
  
      /**
       * Parses the ID, taking a flag to indicate whether {@code ZoneRulesException}
       * should be thrown or not, used in deserialization.
       *
       * @param zoneId  the time-zone ID, not null
       * @param checkAvailable  whether to check if the zone ID is available
       * @return the zone ID, not null
       * @throws DateTimeException if the ID format is invalid
       * @throws ZoneRulesException if checking availability and the ID cannot be found
       */
      static ZoneId of(String zoneId, boolean checkAvailable) {
          Objects.requireNonNull(zoneId, "zoneId");
          if (zoneId.length() <= 1 || zoneId.startsWith("+") || zoneId.startsWith("-")) {
              return ZoneOffset.of(zoneId);
          } else if (zoneId.startsWith("UTC") || zoneId.startsWith("GMT")) {
              return ofWithPrefix(zoneId, 3, checkAvailable);
          } else if (zoneId.startsWith("UT")) {
              return ofWithPrefix(zoneId, 2, checkAvailable);
          }
          return ZoneRegion.ofId(zoneId, checkAvailable);
      }
  
      /**
       * Parse once a prefix is established.
       *
       * @param zoneId  the time-zone ID, not null
       * @param prefixLength  the length of the prefix, 2 or 3
       * @return the zone ID, not null
       * @throws DateTimeException if the zone ID has an invalid format
       */
      private static ZoneId ofWithPrefix(String zoneId, int prefixLength, boolean checkAvailable) {
          String prefix = zoneId.substring(0, prefixLength);
          if (zoneId.length() == prefixLength) {
              return ofOffset(prefix, ZoneOffset.UTC);
          }
          if (zoneId.charAt(prefixLength) != '+' && zoneId.charAt(prefixLength) != '-') {
              return ZoneRegion.ofId(zoneId, checkAvailable);  // drop through to ZoneRulesProvider
          }
          try {
              ZoneOffset offset = ZoneOffset.of(zoneId.substring(prefixLength));
              if (offset == ZoneOffset.UTC) {
                  return ofOffset(prefix, offset);
              }
              return ofOffset(prefix, offset);
          } catch (DateTimeException ex) {
              throw new DateTimeException("Invalid ID for offset-based ZoneId: " + zoneId, ex);
          }
      }
  
      //-----------------------------------------------------------------------
      /**
       * Obtains an instance of {@code ZoneId} from a temporal object.
       * <p>
       * This obtains a zone based on the specified temporal.
       * A {@code TemporalAccessor} represents an arbitrary set of date and time information,
       * which this factory converts to an instance of {@code ZoneId}.
       * <p>
       * A {@code TemporalAccessor} represents some form of date and time information.
       * This factory converts the arbitrary temporal object to an instance of {@code ZoneId}.
       * <p>
       * The conversion will try to obtain the zone in a way that favours region-based
       * zones over offset-based zones using {@link TemporalQueries#zone()}.
       * <p>
       * This method matches the signature of the functional interface {@link TemporalQuery}
       * allowing it to be used as a query via method reference, {@code ZoneId::from}.
       *
       * @param temporal  the temporal object to convert, not null
       * @return the zone ID, not null
       * @throws DateTimeException if unable to convert to a {@code ZoneId}
       */
      public static ZoneId from(TemporalAccessor temporal) {
          ZoneId obj = temporal.query(TemporalQueries.zone());
          if (obj == null) {
              throw new DateTimeException("Unable to obtain ZoneId from TemporalAccessor: " +
                      temporal + " of type " + temporal.getClass().getName());
          }
          return obj;
      }
  
      //-----------------------------------------------------------------------
      /**
       * Constructor only accessible within the package.
       */
      ZoneId() {
          if (getClass() != ZoneOffset.class && getClass() != ZoneRegion.class) {
              throw new AssertionError("Invalid subclass");
          }
      }
  
      //-----------------------------------------------------------------------
      /**
       * Gets the unique time-zone ID.
       * <p>
       * This ID uniquely defines this object.
       * The format of an offset based ID is defined by {@link ZoneOffset#getId()}.
       *
       * @return the time-zone unique ID, not null
       */
      public abstract String getId();
  
      //-----------------------------------------------------------------------
      /**
       * Gets the textual representation of the zone, such as 'British Time' or
       * '+02:00'.
       * <p>
       * This returns the textual name used to identify the time-zone ID,
       * suitable for presentation to the user.
       * The parameters control the style of the returned text and the locale.
       * <p>
       * If no textual mapping is found then the {@link #getId() full ID} is returned.
       *
       * @param style  the length of the text required, not null
       * @param locale  the locale to use, not null
       * @return the text value of the zone, not null
       */
      public String getDisplayName(TextStyle style, Locale locale) {
          return new DateTimeFormatterBuilder().appendZoneText(style).toFormatter(locale).format(toTemporal());
      }
  
      /**
       * Converts this zone to a {@code TemporalAccessor}.
       * <p>
       * A {@code ZoneId} can be fully represented as a {@code TemporalAccessor}.
       * However, the interface is not implemented by this class as most of the
       * methods on the interface have no meaning to {@code ZoneId}.
       * <p>
       * The returned temporal has no supported fields, with the query method
       * supporting the return of the zone using {@link TemporalQueries#zoneId()}.
       *
       * @return a temporal equivalent to this zone, not null
       */
      private TemporalAccessor toTemporal() {
          return new TemporalAccessor() {
              @Override
              public boolean isSupported(TemporalField field) {
                  return false;
              }
              @Override
              public long getLong(TemporalField field) {
                  throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
              }
              @SuppressWarnings("unchecked")
              @Override
              public <R> R query(TemporalQuery<R> query) {
                  if (query == TemporalQueries.zoneId()) {
                      return (R) ZoneId.this;
                  }
                  return TemporalAccessor.super.query(query);
              }
          };
      }
  
      //-----------------------------------------------------------------------
      // Android-removed: ZoneRulesProvider related paragraph
      /**
       * Gets the time-zone rules for this ID allowing calculations to be performed.
       * <p>
       * The rules provide the functionality associated with a time-zone,
       * such as finding the offset for a given instant or local date-time.
       * <p>
       * A time-zone can be invalid if it is deserialized in a Java Runtime which
       * does not have the same rules loaded as the Java Runtime that stored it.
       * In this case, calling this method will throw a {@code ZoneRulesException}.
       * <p>
       * {@link ZoneOffset} will always return a set of rules where the offset never changes.
       *
       * @return the rules, not null
       * @throws ZoneRulesException if no rules are available for this ID
       */
      public abstract ZoneRules getRules();
  
      /**
       * Normalizes the time-zone ID, returning a {@code ZoneOffset} where possible.
       * <p>
       * The returns a normalized {@code ZoneId} that can be used in place of this ID.
       * The result will have {@code ZoneRules} equivalent to those returned by this object,
       * however the ID returned by {@code getId()} may be different.
       * <p>
       * The normalization checks if the rules of this {@code ZoneId} have a fixed offset.
       * If they do, then the {@code ZoneOffset} equal to that offset is returned.
       * Otherwise {@code this} is returned.
       *
       * @return the time-zone unique ID, not null
       */
      public ZoneId normalized() {
          try {
              ZoneRules rules = getRules();
              if (rules.isFixedOffset()) {
                  return rules.getOffset(Instant.EPOCH);
              }
          } catch (ZoneRulesException ex) {
              // invalid ZoneRegion is not important to this method
          }
          return this;
      }
  
      //-----------------------------------------------------------------------
      /**
       * Checks if this time-zone ID is equal to another time-zone ID.
       * <p>
       * The comparison is based on the ID.
       *
       * @param obj  the object to check, null returns false
       * @return true if this is equal to the other time-zone ID
       */
      @Override
      public boolean equals(Object obj) {
          if (this == obj) {
             return true;
          }
          if (obj instanceof ZoneId) {
              ZoneId other = (ZoneId) obj;
              return getId().equals(other.getId());
          }
          return false;
      }
  
      /**
       * A hash code for this time-zone ID.
       *
       * @return a suitable hash code
       */
      @Override
      public int hashCode() {
          return getId().hashCode();
      }
  
      //-----------------------------------------------------------------------
      /**
       * Defend against malicious streams.
       *
       * @param s the stream to read
       * @throws InvalidObjectException always
       */
      private void readObject(ObjectInputStream s) throws InvalidObjectException {
          throw new InvalidObjectException("Deserialization via serialization delegate");
      }
  
      /**
       * Outputs this zone as a {@code String}, using the ID.
       *
       * @return a string representation of this time-zone ID, not null
       */
      @Override
      public String toString() {
          return getId();
      }
  
      //-----------------------------------------------------------------------
      /**
       * Writes the object using a
       * <a href="../../serialized-form.html#java.time.Ser">dedicated serialized form</a>.
       * @serialData
       * <pre>
       *  out.writeByte(7);  // identifies a ZoneId (not ZoneOffset)
       *  out.writeUTF(getId());
       * </pre>
       * <p>
       * When read back in, the {@code ZoneId} will be created as though using
       * {@link #of(String)}, but without any exception in the case where the
       * ID has a valid format, but is not in the known set of region-based IDs.
       *
       * @return the instance of {@code Ser}, not null
       */
      // this is here for serialization Javadoc
      private Object writeReplace() {
          return new Ser(Ser.ZONE_REGION_TYPE, this);
      }
  
      abstract void write(DataOutput out) throws IOException;
  
  }
  