code: def get_authenticated_connection(self, user, passwd, db='admin', ssl=True):
          
          # Attempt to establish an authenticated connection.
          try:
              connection = self.get_connection(ssl=ssl)
              connection[db].authenticate(user, passwd)
              return connection
  
          # Catch exception here for logging, then just re-raise.
          except pymongo.errors.OperationFailure as ex:
              logger.exception(ex)
              raise
docs: Get an authenticated connection to this instance.
  
          :param str user: The username to use for authentication.
          :param str passwd: The password to use for authentication.
          :param str db: The name of the database to authenticate against. Defaults to ``'Admin'``.
          :param bool ssl: Use SSL/TLS if available for this instance. Defaults to ``True``.
          :raises: :py:class:`pymongo.errors.OperationFailure` if authentication fails.