content: // Protocol Buffers - Google's data interchange format
  // Copyright 2008 Google Inc.  All rights reserved.
  // https://developers.google.com/protocol-buffers/
  //
  // 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.
  //     * Neither the name of Google Inc. 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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  // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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  // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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  // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  
  package com.google.protobuf;
  
  /**
   * Base interface for methods common to {@link MessageLite} and {@link MessageLite.Builder} to
   * provide type equivalency.
   *
   * @author jonp@google.com (Jon Perlow)
   */
  public interface MessageLiteOrBuilder {
    /**
     * Get an instance of the type with no fields set. Because no fields are set, all getters for
     * singular fields will return default values and repeated fields will appear empty. This may or
     * may not be a singleton. This differs from the {@code getDefaultInstance()} method of generated
     * message classes in that this method is an abstract method of the {@code MessageLite} interface
     * whereas {@code getDefaultInstance()} is a static method of a specific class. They return the
     * same thing.
     */
    MessageLite getDefaultInstanceForType();
  
    /**
     * Returns true if all required fields in the message and all embedded messages are set, false
     * otherwise.
     *
     * <p>See also: {@link MessageOrBuilder#getInitializationErrorString()}
     */
    boolean isInitialized();
  }
  