code: def word_difference_score(s1, s2):
      """Returns the number of words that are non-overlapping between s1 and
      s2."""
      s1_words = get_words_cached(s1)
      s2_words = get_words_cached(s2)
      min_length = min(len(s1_words), len(s2_words))
      if min_length == 0:
          return 0
      s1_words = s1_words[:min_length]
      s2_words = s2_words[:min_length]
      return (s1_words != s2_words).sum()
  
file_path: TextAttack/textattack/goal_functions/text/non_overlapping_output.py
imports: import functools
  import numpy
  from textattack.shared.utils import words_from_text
  from .text_to_text_goal_function import TextToTextGoalFunction
label_desc: Use image node_id 2 for calling a global function with example usage: word_difference_score(s1, s2) and returns: unknown, int