docs: def process_op(self, rc, nbytes, overlap):
          """
          Handles the possible completion or re-queueing if conditions haven't
          been met (the `complete` callable returns false) of a overlapped request.
          """
          act = overlap.object
          overlap.object = None
          if act in self.tokens:
              ol, perform, complete = self.tokens[act]
              assert ol is overlap
              if rc == 0:
                  ract = self.try_run_act(act, complete, rc, nbytes)
                  if ract:
                      del self.tokens[act]
                      win32file.CancelIo(act.sock._fd.fileno())
                      return ract, act.coro
                  else:
                      # operation hasn't completed yet (not enough data etc)
                      # read it in the iocp
                      self.request_generic(act, act.coro, perform, complete)
  
  
              else:
                  #looks like we have a problem, forward it to the coroutine.
  
                  # this needs some research: ERROR_NETNAME_DELETED, need to reopen
                  #the accept sock ?! something like:
                  #    warnings.warn("ERROR_NETNAME_DELETED: %r. Re-registering operation." % op)
                  #    self.registered_ops[op] = self.run_iocp(op, coro)
                  del self.tokens[act]
                  win32file.CancelIo(act.sock._fd.fileno())
                  return CoroutineException((
                      SocketError, SocketError(
                          (rc, "%s on %r" % (ctypes.FormatError(rc), act))
                      )
                  )), act.coro
          else:
              import warnings
              warnings.warn("Unknown token %s" % act)