@Override
  public void setWriteChecksum(boolean writeChecksum) {
    fs.setWriteChecksum(writeChecksum);
  }
@Test
  public void testWriteChecksumPassthru() {
    FileSystem mockFs = mock(FileSystem.class);
    FileSystem fs = new FilterFileSystem(mockFs);

    fs.setWriteChecksum(false);
    verify(mockFs).setWriteChecksum(eq(false));
    reset(mockFs);
    fs.setWriteChecksum(true);
    verify(mockFs).setWriteChecksum(eq(true));
  }