Copy Function

    def copy(self):
        def get_descendants(_node):
            descendants = []

            _children = self.get_children(_node)
            for _child in _children:
                descendants.append(_child)
                _nodes = self.get_children(_child)
                if _nodes:
                    descendants += self.get_descendants(_child)

            return descendants

        self.was_cut = False
        self.tags_remove_all('copy', 'selected')
        self.refresh_tags()

        self.popup.enable_items(['paste'])
        self.pointer_x, self.pointer_y = self.winfo_toplevel().winfo_pointerxy()

        items = []
        selections = sorted(list(self.selection()))
        for node in selections:
            item = self.item(node)
            _type = item['values'][0]
            _open = item['open']
            items.append(node)

            if not _open and _type == 'Menu':
                items += get_descendants(node)

        for item in items:
            self.tags_add(item, ['copy', 'selected'])
            self.tags_remove(item, ['odd', 'even'])