def remove(self, elem):
        """Remove a requirement.

        :param elem: a string or :class:`Requirement` instance.
        """
        if isinstance(elem, text_type):
            for requirement in self:
                if requirement.package == elem:
                    return super(Requirements, self).remove(requirement)
        return super(Requirements, self).remove(elem)
async def echo_client_streams(reader, writer):
    sock = writer.get_extra_info('socket')
    try:
        sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
    except (OSError, NameError):
        pass
    if PRINT:
        print('Connection from', sock.getpeername())
    while True:
        data = await reader.read(1000000)
        if not data:
            break
        writer.write(data)
    if PRINT:
        print('Connection closed')
    writer.close()