def add(self, recv):
        """
        Add a :class:`mitogen.core.Receiver`, :class:`Select` or
        :class:`mitogen.core.Latch` to the select.

        :raises mitogen.select.Error:
            An attempt was made to add a :class:`Select` to which this select
            is indirectly a member of.
        """
        if isinstance(recv, Select):
            recv._check_no_loop(self)

        self._receivers.append(recv)
        if recv.notify is not None:
            raise Error(self.owned_msg)

        recv.notify = self._put
        # Avoid race by polling once after installation.
        if not recv.empty():
            self._put(recv)
Add a :class:`mitogen.core.Receiver`, :class:`Select` or
        :class:`mitogen.core.Latch` to the select.

        :raises mitogen.select.Error:
            An attempt was made to add a :class:`Select` to which this select
            is indirectly a member of.