docs: def _write(self, body, id):
          """
          Respond to a WRITE command, sending some data over a virtual channel
          created by VIRTUAL.  The answer is simply an acknowledgement, as it is
          simply meant to note that the write went through without errors.
  
          An occurrence of I{Write} on the wire, together with the response
          generated by this method, might have this apperance::
  
              C: -Command: Write
              C: -Ask: 1
              C: -Length: 13
              C: Id: glyph@divmod.com->radix@twistedmatrix.com:q2q-example:0
              C:
              C: HELLO WORLD
              C:
              S: -Answer: 1
              S:
  
          """
          if id not in self.connections:
              raise error.ConnectionDone()
          connection = self.connections[id]
          connection.dataReceived(body)
          return {}