Return a generator of the IDs of multiplicons that are neither
            seeding 'pairs' in level 2 multiplicons, nor leaves.

            Arguments:

            o redundant - if true, report redundant multiplicons

def get_multiplicon_intermediates(self, redundant=False):
        """ Return a generator of the IDs of multiplicons that are neither
            seeding 'pairs' in level 2 multiplicons, nor leaves.

            Arguments:

            o redundant - if true, report redundant multiplicons
        """
        for node in self._multiplicon_graph.nodes():
            if len(self._multiplicon_graph.in_edges(node)) and \
               len(self._multiplicon_graph.out_edges(node)):
                if not self.is_redundant_multiplicon(node):
                    yield node
                elif redundant:
                    yield node
                else:
                    continue
            else:
                continue