public TransformWatermarks getWatermarks(ExecutableT executable) {
    return transformToWatermarks.get(executable);
  }
@Test
  public void getWatermarkForUntouchedTransform() {
    TransformWatermarks watermarks = manager.getWatermarks(graph.getProducer(impulse));

    assertThat(watermarks.getInputWatermark(), equalTo(BoundedWindow.TIMESTAMP_MIN_VALUE));
    assertThat(watermarks.getOutputWatermark(), equalTo(BoundedWindow.TIMESTAMP_MIN_VALUE));
  }