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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _open_all_rings(self):
 """ Having already generated all unique fragments that did not require ring opening, now we want to also obtain fragments that do require opening. We achieve this by looping through all unique fragments and opening each bond present in any ring we find. We also temporarily add the principle molecule graph to self.unique_fragments so that its rings are opened as well. """

        self.unique_fragments.insert(0, self.mol_graph)
        for fragment in self.unique_fragments:
            ring_edges = fragment.find_rings()
            if ring_edges != []:
                for bond in ring_edges[0]:
                    new_fragment = open_ring(fragment, [bond], self.opt_steps)
                    found = False
                    for unique_fragment in self.unique_fragments:
                        if unique_fragment.isomorphic_to(new_fragment):
                            found = True
                            break
                    if not found:
                        self.unique_fragments_from_ring_openings.append(new_fragment)
                        self.unique_fragments.append(new_fragment)
        # Finally, remove the principle molecule graph:
        self.unique_fragments.pop(0)