def sendFileDescriptor(descriptor):
        """
        Send a duplicate of this (file, socket, pipe, etc) descriptor to the
        other end of this connection.

        The send is non-blocking and will be queued if it cannot be performed
        immediately.  The send will be processed in order with respect to other
        C{sendFileDescriptor} calls on this transport, but not necessarily with
        respect to C{write} calls on this transport.  The send can only be
        processed if there are also bytes in the normal connection-oriented send
        buffer (ie, you must call C{write} at least as many times as you call
        C{sendFileDescriptor}).

        @param descriptor: An C{int} giving a valid file descriptor in this
            process.  Note that a I{file descriptor} may actually refer to a
            socket, a pipe, or anything else POSIX tries to treat in the same
            way as a file.

        @return: L{None}
        """

        Send a duplicate of this (file, socket, pipe, etc) descriptor to the
        other end of this connection.

        The send is non-blocking and will be queued if it cannot be performed
        immediately.  The send will be processed in order with respect to other
        C{sendFileDescriptor} calls on this transport, but not necessarily with
        respect to C{write} calls on this transport.  The send can only be
        processed if there are also bytes in the normal connection-oriented send
        buffer (ie, you must call C{write} at least as many times as you call
        C{sendFileDescriptor}).

        @param descriptor: An C{int} giving a valid file descriptor in this
            process.  Note that a I{file descriptor} may actually refer to a
            socket, a pipe, or anything else POSIX tries to treat in the same
            way as a file.

        @return: L{None}
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/internet/interfaces.py