@Test
public void build_checksContentTypeMetadata() {

  CreateObjectOptions.builder()
      .setMetadata(ImmutableMap.of("Innocuous-Type", "".getBytes(UTF_8)))
      .build();
  assertThrows(
      IllegalArgumentException.class,
      () ->
          CreateObjectOptions.builder()
              .setMetadata(ImmutableMap.of("Content-Type", "".getBytes(UTF_8)))
              .build());
}