#each_strongly_connected_component	TSort#each_strongly_connected_component
#each_strongly_connected_component_from	TSort#each_strongly_connected_component_from
#strongly_connected_components	TSort#strongly_connected_components
#tsort	TSort#tsort
#tsort_each	TSort#tsort_each
#tsort_each_child	TSort#tsort_each_child
#tsort_each_node	TSort#tsort_each_node
