'The C{flags} argument to L{recv1msg} is passed on to the underlying
C{recvmsg} call, to affect it in whatever way is defined by those
flags.'

def test_flags(self):

    (reader, writer) = socketpair(AF_UNIX)
    exc = self.assertRaises(error, recv1msg, reader.fileno(), MSG_DONTWAIT)
    self.assertEqual(exc.args[0], errno.EAGAIN)
