Dictionary with errors of an *of-rule mapped to the index of the
            definition it occurred in. Returns :obj:`None` if not applicable.

def definitions_errors(self):
        """ Dictionary with errors of an *of-rule mapped to the index of the
            definition it occurred in. Returns :obj:`None` if not applicable.
            """
        if not self.is_logic_error:
            return None

        result = defaultdict(list)
        for error in self.child_errors:
            i = error.schema_path[len(self.schema_path)]
            result[i].append(error)
        return result