@Test
public void testHttpHeadersProperties_singleHeader() {

  Configuration config = new Configuration();
  config.set(GCS_HTTP_HEADERS.getKey() + "header-key", "val=ue");
  GoogleCloudStorageFileSystemOptions options =
      GoogleHadoopFileSystemConfiguration.getGcsFsOptionsBuilder(config).build();
  assertThat(options.getCloudStorageOptions().getHttpRequestHeaders())
      .containsExactly("header-key", "val=ue");
}