content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you under the Apache License, Version 2.0 (the
   * "License"); you may not use this file except in compliance
   * with the License.  You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.apache.beam.runners.local;
  
  import org.apache.beam.sdk.values.WindowedValue;
  import org.checkerframework.checker.nullness.qual.Nullable;
  import org.joda.time.Instant;
  
  /** An immutable collection of elements which are part of a {@code PCollection}. */
  public interface Bundle<T, CollectionT> extends Iterable<WindowedValue<T>> {
    /** Returns the PCollection that the elements of this bundle belong to. */
    @Nullable
    CollectionT getPCollection();
  
    /**
     * Returns the key that was output in the most recent {@code GroupByKey} in the execution of this
     * bundle.
     */
    StructuralKey<?> getKey();
  
    /**
     * Return the minimum timestamp among elements in this bundle.
     *
     * <p>This should be equivalent to iterating over all of the elements within a bundle and
     * selecting the minimum timestamp from among them.
     */
    Instant getMinimumTimestamp();
  
    /**
     * Returns the processing time output watermark at the time the producing {@code Executable}
     * committed this bundle. Downstream synchronized processing time watermarks cannot progress past
     * this point before consuming this bundle.
     *
     * <p>This value is no greater than the earliest incomplete processing time or synchronized
     * processing time at the time this bundle was committed, including any timers that fired to
     * produce this bundle.
     */
    Instant getSynchronizedProcessingOutputWatermark();
  }
  