def fix_identities(self, uniq=None):
        """Make pattern-tree tips point to same object if they are equal."""
        if not hasattr(self, 'children'):
            return self
        uniq = list(set(self.flat())) if uniq is None else uniq
        for i, c in enumerate(self.children):
            if not hasattr(c, 'children'):
                assert c in uniq
                self.children[i] = uniq[uniq.index(c)]
            else:
                c.fix_identities(uniq)
dataset/ETHPy150Open benoitc/gaffer/gaffer/docopt.py/Pattern.fix_identities/original