  @Test
  public void negativeTest() throws ODPSConsoleException, OdpsException {

    UnSetCommand cmd = UnSetCommand.parse("unse testkey", null);
    assertNull(cmd);

    cmd = UnSetCommand.parse("unset ", null);
    assertNull(cmd);

    cmd = UnSetCommand.parse("unalia testkey\n", null);
    assertNull(cmd);

    cmd  = UnSetCommand.parse("unalias \r\n", null);
    assertNull(cmd);
  }