public static <M> Trigger<M> timeSinceFirstMessage(Duration duration) {
    return new TimeSinceFirstMessageTrigger<M>(duration);
  }
Creates a trigger that fires after the specified duration has passed since the first message in
the pane.

@param duration the duration since the first element
@param <M> the type of input message in the window
@return the created trigger
samza-api/src/main/java/org/apache/samza/operators/triggers/Triggers.java