Return all Loop instances that can be extracted from a graph.

        :param graph:   The graph to analyze.

        :return:        A list of all the Loop instances that were found in the graph.

def _parse_loops_from_graph(self, graph):
        """
        Return all Loop instances that can be extracted from a graph.

        :param graph:   The graph to analyze.

        :return:        A list of all the Loop instances that were found in the graph.
        """
        outtop = []
        outall = []
        for subg in networkx.strongly_connected_component_subgraphs(graph):
            if len(subg.nodes()) == 1:
                if len(list(subg.successors(list(subg.nodes())[0]))) == 0:
                    continue
            thisloop, allloops = self._parse_loop_graph(subg, graph)
            if thisloop is not None:
                outall += allloops
                outtop.append(thisloop)
        return outtop, outall