@Override
    public Committer closeForCommit() throws IOException {
        lock();
        try {
            closeAndUploadPart();
            return upload.snapshotAndGetCommitter();
        } finally {
            unlock();
        }
    }
@Test
    public void noWritesShouldResolveInAnEmptyFile() throws IOException {
        RecoverableFsDataOutputStream.Committer committer = streamUnderTest.closeForCommit();
        committer.commit();

        assertThat(multipartUploadUnderTest, hasContent(new byte[0]));
    }