public BigtableConfig withProjectId(ValueProvider<String> projectId) {
    checkArgument(projectId != null, "Project Id of BigTable can not be null");
    return toBuilder().setProjectId(projectId).build();
  }
@Test
  public void testWithProjectId() {
    assertEquals(PROJECT_ID.get(), config.withProjectId(PROJECT_ID).getProjectId().get());

    thrown.expect(IllegalArgumentException.class);
    config.withProjectId(null);
  }