code: def get_connection(self, **kwargs):
          
          if self.is_rtscts():
              return RTSCTSConnection(self, **kwargs)
  
          if self.is_dsrdtr():
              return DSRDTRConnection(self, **kwargs)
  
          else:
              raise RuntimeError('Serial protocol "%s" is not available.' % (
                      self.protocol))
docs: Return a serial connection implementation suitable for the specified
          protocol. Raises ``RuntimeError`` if there is no implementation for
          the given protocol.
  
          .. warn::
  
              This may be a little bit confusing since there is no effective
              connection but an implementation of a connection pattern.