docstr: Helper function of _get_new_number, replace a number with another
  random number within the range of self.max_change.
code: def _alter_number(self, num):
      """Helper function of _get_new_number, replace a number with another
      random number within the range of self.max_change."""
      if num not in [0, 2, 4]:
          change = int(num * self.max_change) + 1
          if num >= 0:
              num_list = np.random.randint(
                  max(num - change, 1), num + change, self.n
              )
          else:
              num_list = np.random.randint(
                  num - change, min(0, num + change), self.n
              )
          return num_list
      return []
  
file_path: TextAttack/textattack/transformations/word_swaps/word_swap_change_number.py
imports: import more_itertools
  from num2words import num2words
  import numpy
  from word2number import w2n
  from .word_swap import WordSwap
label_desc: Use image node_id 4 for calling the WordSwapChangeNumber obj's underlying member method code with example usage: obj._alter_number(num) and returns: list, num_list