_node_add_without_peer_leaflist

        Low-level api: Apply delta child_other to node_sum when there is no peer
        of child_other can be found under node_sum. child_other is a leaf-list
        node. Element node_sum will be modified during the process.

        Parameters
        ----------

        node_sum : `Element`
            A config node in a config tree.

        child_other : `Element`
            A child of a config node in another config tree. This child has no
            peer under node_sum.

        Returns
        -------

        None
            There is no return of this method.

def _node_add_without_peer_leaflist(self, node_sum, child_other):
        '''_node_add_without_peer_leaflist

        Low-level api: Apply delta child_other to node_sum when there is no peer
        of child_other can be found under node_sum. child_other is a leaf-list
        node. Element node_sum will be modified during the process.

        Parameters
        ----------

        node_sum : `Element`
            A config node in a config tree.

        child_other : `Element`
            A child of a config node in another config tree. This child has no
            peer under node_sum.

        Returns
        -------

        None
            There is no return of this method.
        '''

        s_node = self.device.get_schema_node(child_other)
        e = deepcopy(child_other)
        scope = node_sum.getchildren()
        siblings = self._get_sequence(scope, child_other.tag, node_sum)
        if s_node.get('ordered-by') == 'user' and \
           child_other.get(insert_tag) is not None:
            if child_other.get(insert_tag) == 'first':
                if siblings:
                    siblings[0].addprevious(self._del_attrib(e))
                else:
                    node_sum.append(self._del_attrib(e))
            elif child_other.get(insert_tag) == 'last':
                if siblings:
                    siblings[-1].addnext(self._del_attrib(e))
                else:
                    node_sum.append(self._del_attrib(e))
            elif child_other.get(insert_tag) == 'before':
                if child_other.get(value_tag) is None:
                    _inserterror('before', self.device.get_xpath(child_other),
                                 'value')
                siblings = node_sum.findall(child_other.tag)
                sibling = [s for s in siblings
                           if s.text == child_other.get(value_tag)]
                if not sibling:
                    path = self.device.get_xpath(child_other)
                    value = child_other.get(value_tag)
                    _inserterror('before', path, 'value', value)
                sibling[0].addprevious(self._del_attrib(e))
            elif child_other.get(insert_tag) == 'after':
                if child_other.get(value_tag) is None:
                    _inserterror('after', self.device.get_xpath(child_other),
                                 'value')
                siblings = node_sum.findall(child_other.tag)
                sibling = [s for s in siblings
                           if s.text == child_other.get(value_tag)]
                if not sibling:
                    path = self.device.get_xpath(child_other)
                    value = child_other.get(value_tag)
                    _inserterror('after', path, 'value', value)
                sibling[0].addnext(self._del_attrib(e))
        else:
            if siblings:
                siblings[-1].addnext(self._del_attrib(e))
            else:
                node_sum.append(self._del_attrib(e))