Return an event object suitable for the named transport

def get_master_event(opts, sock_dir, listen=True, io_loop=None, raise_errors=False, keep_loop=False):
    '''
    Return an event object suitable for the named transport
    '''
    # TODO: AIO core is separate from transport
    if opts['transport'] in ('zeromq', 'tcp', 'detect'):
        return MasterEvent(sock_dir, opts, listen=listen, io_loop=io_loop, raise_errors=raise_errors, keep_loop=keep_loop)