public Module configure(Container container) {
    this.container = checkNotNull(container);
    configureModule();
    return this;
  }
@Test(expected = NullPointerException.class)
  public void configure_throws_NPE_if_container_is_empty() {
    new Module() {
      @Override
      protected void configureModule() {
        // empty
      }
    }.configure(null);
  }