code: def get_tree_str(tree):
      """get str from sel tree"""
      str_list = list()
      for element in tree:
          if isinstance(element, str):
              str_list += [element]
      return " ".join(str_list)
  
imports: from collections import Counter
  import logging
  from nltk.tree import ParentedTree
  import re
  from typing import Tuple, List, Dict
  from ...extraction.constants import null_span, type_start, type_end, span_start
  from ...extraction.predict_parser.predict_parser import PredictParser
  from ...extraction.predict_parser.utils import fix_unk_from_text
label_desc: Use image node_id 8 for calling a global function with example usage: get_tree_str(tree) and returns: str