@VisibleForTesting
  static StreamExecutionEnvironment createStreamExecutionEnvironment(FlinkPipelineOptions options) {
    return createStreamExecutionEnvironment(
        options,
        MoreObjects.firstNonNull(options.getFilesToStage(), Collections.emptyList()),
        options.getFlinkConfDir());
  }
@Test
  public void useDefaultParallelismFromContextStreaming() {
    FlinkPipelineOptions options = getDefaultPipelineOptions();
    options.setRunner(TestFlinkRunner.class);

    StreamExecutionEnvironment sev =
        FlinkExecutionEnvironments.createStreamExecutionEnvironment(options);

    assertThat(sev, instanceOf(LocalStreamEnvironment.class));
    assertThat(options.getParallelism(), is(LocalStreamEnvironment.getDefaultLocalParallelism()));
    assertThat(sev.getParallelism(), is(LocalStreamEnvironment.getDefaultLocalParallelism()));
  }