Assembly containing only assigned regions (i.e. regions with contiguous KnobsIntoHoles.

def get_coiledcoil_region(self, cc_number=0, cutoff=7.0, min_kihs=2):
        """ Assembly containing only assigned regions (i.e. regions with contiguous KnobsIntoHoles. """
        g = self.filter_graph(self.graph, cutoff=cutoff, min_kihs=min_kihs)
        ccs = sorted(networkx.connected_component_subgraphs(g, copy=True),
                                 key=lambda x: len(x.nodes()), reverse=True)
        cc = ccs[cc_number]
        helices = [x for x in g.nodes() if x.number in cc.nodes()]
        assigned_regions = self.get_assigned_regions(helices=helices, include_alt_states=False, complementary_only=True)
        coiledcoil_monomers = [h.get_slice_from_res_id(*assigned_regions[h.number]) for h in helices]
        return Assembly(coiledcoil_monomers)