def DEFINE_list(name, default, help):
 CONFIG.AddOption(type_info.List(name=name, default=default, description=help, validator=type_info.String()))

def DEFINE_list ( name , default , help ) : CONFIG . AddOption ( type_info . List ( name = name , default = default , description = help , validator = type_info . String ( ) ) )
registers a flag whose value is a comma-separated list of strings .