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 backtype.storm.windowing;
  
  /**
   * An event is a wrapper object that gets stored in the window.
   *
   * @param <T> the type of the object thats wrapped. E.g Tuple
   */
  interface Event<T> {
      /**
       * The event timestamp in millis. This could be the time
       * when the source generated the tuple or the time
       * when the tuple was received by a bolt.
       *
       * @return the event timestamp in milliseconds.
       */
      long getTimestamp();
  
      /**
       * Returns the wrapped object, E.g. a tuple
       *
       * @return the wrapped object.
       */
      T get();
  
      /**
       * If this is a watermark event or not. Watermark events are used
       * for tracking time while processing event based ts.
       *
       * @return true if this is a watermark event
       */
      boolean isWatermark();
  }
  