code: def add_connection(self, addr, **kwargs):
          
          if addr not in self._connections:
              self.connections[addr] = {}
              for k, v in kwargs.items():
                  self.connections[addr][k] = v
              return True
          return False
docs: Add an agent with given address to current :attr:`connections` with
          given information.
  
          Does nothing if address is already in :attr:`connections`. Given
          ``**kwargs`` are stored as key-value pairs to ``connections[addr]``
          dictionary.
  
          :param str addr:
              Address of the agent to be added
          :returns:
              ``True`` if the agent was successfully added, ``False`` otherwise.