def _build_tree(self):
        """
        Build a full or a partial tree, depending on the groups/sub-groups specified.
        """

        groups = self._groups or self.get_children_paths(self.root_path)
        for group in groups:
            node = Node(name=group, parent=self.root)
            self.root.children.append(node)
            self._init_sub_groups(node)
Build a full or a partial tree, depending on the groups/sub-groups specified.