class_docstr: Lineages of trials for workers in PBT
  
  This class regroup all lineages of trials generated by PBT for a given experiment.
  
  Each lineage is a path from a leaf trial (highest fidelity level) up to the root
  (lowest fidelity level). Multiple lineages can fork from the same root, forming a tree.
  A Lineages object may reference multiple trees of lineages. Iterating a Lineages object will
  iterate on the roots of these trees.
docstr: Iterate over the roots of the Lineages
docstr_tok: ["Iterate","over","the","roots","of","the","Lineages"]
code: def __iter__(self):
      """Iterate over the roots of the Lineages"""
      return iter(self._lineage_roots)
  
imports: from __future__ import annotations
  import copy
  import logging
  import time
  from typing import Any, ClassVar, Iterable, Sequence
  import numpy
  from orion.algo.base import BaseAlgorithm
  from orion.algo.pbt.exploit import exploit_factory
  from orion.algo.pbt.explore import explore_factory
  from orion.algo.random import Random
  from orion.algo.space import Fidelity, Space
  from orion.core.utils.flatten import flatten
  from orion.core.utils.tree import TreeNode
  from orion.core.worker.transformer import TransformedDimension
  from orion.core.worker.trial import Trial
label_desc: Use image node_id 3 for calling the Lineages obj's underlying member method code with example usage: obj.__iter__() and returns: iter