'Init.
name: name to give controller.
ryuArgs: arguments and modules to pass to Ryu'

def __init__(self, name, *ryuArgs, **kwargs):

    homeDir = quietRun('printenv    HOME').strip('\r\n')
    ryuCoreDir = ('%s/ryu/ryu/app/' % homeDir)
    if (not ryuArgs):
        warn('warning:    no    Ryu    modules    specified;    running    simple_switch    only\n')
        ryuArgs = [(ryuCoreDir + 'simple_switch.py')]
    elif (type(ryuArgs) not in (list, tuple)):
        ryuArgs = [ryuArgs]
    Controller.__init__(self, name, command='ryu-manager', cargs=('--ofp-tcp-listen-port    %s    ' + '    '.join(ryuArgs)), cdir=ryuCoreDir, **kwargs)
