<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get_unique_name(self):
 """Return the unique name of the D-BUS connection."""

        self._name_acquired.wait()
        if self._error:
            raise compat.saved_exc(self._error)
        elif self._transport is None:
            raise DbusError('not connected')
        return self._unique_name