docs: def _open_connection(self):
          """ Open a new connection socket to the CPS."""
          if self._scheme == 'unix':
              self._connection = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM, 0)
              self._connection.connect(self._path)
          elif self._scheme == 'tcp':
              self._connection = socket.socket(socket.AF_INET, socket.SOCK_STREAM, socket.SOL_TCP)
              self._connection.connect((self._host, self._port))
          elif self._scheme == 'http':
              self._connection =  httplib.HTTPConnection(self._host, self._port, strict=False)
          else:
              raise ConnectionError("Connection scheme not recognized!")