def mkchannel(ctype=Channel, wtype=ChannelWriter, rtype=ChannelReader):
 c = ctype()
 wc = wtype(c)
 rc = rtype(c)
 return (wc, rc)

def mkchannel ( ctype = Channel , wtype = ChannelWriter , rtype = ChannelReader ) : c = ctype ( ) wc = wtype ( c ) rc = rtype ( c ) return ( wc , rc )
create a channel .