docs: def close(self):
          """Closes the SSH connection if the connection is UP."""
          if not self.connected:
              return None
          if self.config is not None:
              if self.config.changed() and not self.config.committed():
                  try:
                      self.config.discard()  # if configuration changed and not committed, will rollback
                  except pyPluribus.exceptions.ConfigurationDiscardError as discarderr:  # bad luck.
                      raise pyPluribus.exceptions.ConnectionError("Could not discard the configuration: \
                          {err}".format(err=discarderr))
          self._connection.close()  # close SSH connection
          self.config = None  # reset config object
          self._connection = None  #
          self.connected = False