class_docstr: A Node instance is used for composing tree-based structures.
class_docstr_tok: ["A","Node","instance","is","used","for","composing","tree-based","structures","."]
docstr: Flag to identify whether the node is a left child.
docstr_tok: ["Flag","to","identify","whether","the","node","is","a","left","child","."]
code: def flag(self) -> bool:
      """Flag to identify whether the node is a left child."""
  
      return self._flag
  
imports: from __future__ import annotations
  from typing import Any, Dict, List, Optional, Union
  import numpy
  import opytimizer.utils.constant
  import opytimizer.utils.exception
label_desc: Use image node_id 16 for calling the Node obj's underlying member method code with example usage: obj.flag() and returns: self