def _group_kids(self, node_one, node_two):
in_1_not_in_2 = []<EOL>in_2_not_in_1 = []<EOL>in_1_and_in_2 = []<EOL>for child in node_one.getchildren():<EOL><INDENT>peers = self._get_peers(child, node_two)<EOL>if len(peers) < <NUM_LIT:1>:<EOL><INDENT>in_1_not_in_2.append(child)<EOL><DEDENT>elif len(peers) > <NUM_LIT:1>:<EOL><INDENT>raise ConfigError('<STR_LIT>'.format(self.device.get_xpath(child)))<EOL><DEDENT>else:<EOL><INDENT>in_1_and_in_2.append((child, peers[<NUM_LIT:0>]))<EOL><DEDENT><DEDENT>for child in node_two.getchildren():<EOL><INDENT>peers = self._get_peers(child, node_one)<EOL>if len(peers) < <NUM_LIT:1>:<EOL><INDENT>in_2_not_in_1.append(child)<EOL><DEDENT>elif len(peers) > <NUM_LIT:1>:<EOL><INDENT>raise ConfigError('<STR_LIT>'.format(self.device.get_xpath(child)))<EOL><DEDENT>else:<EOL><INDENT>pass<EOL><DEDENT><DEDENT>return (in_1_not_in_2, in_2_not_in_1, in_1_and_in_2)<EOL>
_group_kids

        Low-level api: Consider an Element node in a Config instance. Now
        we have two Config instances and we want to compare two corresponding
        Element nodes. This method group children of these nodes in three
        categories: some only exist in node_one, some only exist in node_two,
        and some chiildren of node_one have peers in node_two.

        Parameters
        ----------

        node_one : `Element`
            An Element node in one Config instance.

        node_two : `Element`
            An Element node in the other Config instance.

        Returns
        -------

        tuple
            There are three elements in the tuple. The first element is a list
            of children of node_one that do not have any peers in node_two. The
            second element is a list of children of node_two that do not have
            any peers in node_one. The last element is a list of tuples, and
            each tuple represents a pair of peers.