Enable extraction of what a functor requires from its args.
Enable extraction of what a functor requires from its args.

openstack/taskflow,varunarya10/taskflow,citrix-openstack-build/taskflow,junneyang/taskflow,jimbobhickville/taskflow,citrix-openstack-build/taskflow,jessicalucci/TaskManagement,openstack/taskflow,varunarya10/taskflow,jessicalucci/TaskManagement,pombredanne/taskflow-1,jimbobhickville/taskflow,pombredanne/taskflow-1,junneyang/taskflow