@Override
  public String getFileChecksum(Path sourceFile)
      throws IOException {
    FileSystem fs = sourceFile.getFileSystem(this.conf);
    try (FSDataInputStream in = fs.open(sourceFile)) {
      return this.checksum.computeChecksum(in);
    }
  }
@Test
  public void testChecksum() throws Exception {
    String filename = "test1.txt";
    Path file = makeFile(filename);
    assertEquals(inputChecksumSHA256, client.getFileChecksum(file));
  }