code: def test_insert_whitespace_chars(self) -> None:
      augmented_every_char = txtaugs.insert_whitespace_chars(
          self.texts, "all", 1.0, False
      )
      # Separator inserted between every character (including spaces/punctuation).
      self.assertEqual(
          augmented_every_char,
          [
              "T h e   q u i c k   b r o w n   ' f o x '   c o u l d n ' t   "
              "j u m p   o v e r   t h e   g r e e n ,   g r a s s y   h i l l ."
          ],
      )
      augmented_per_word = txtaugs.insert_whitespace_chars(
          self.texts, "word", 1.0, False
      )
      # Each word uses a different separator; no separators around whitespace.
      self.assertEqual(
          augmented_per_word,
          [
              "T\nh\ne q u i c k b\rr\ro\rw\rn '\nf\no\nx\n' c o u l d n ' t "
              "j u m p o\rv\re\rr t\x0bh\x0be g\x0br\x0be\x0be\x0bn\x0b, "
              "g\nr\na\ns\ns\ny h\ni\nl\nl\n."
          ],
      )
      augmented_wider_cadence = txtaugs.insert_whitespace_chars(
          self.texts, "all", 2.7, False
      )
      # Separators are every 2-3 (avg. 2.7) characters.
      self.assertEqual(
          augmented_wider_cadence,
          [
              "The  qu ick  b row n ' fo x'  cou ld n't  ju mp  ov er  the  "
              "g ree n,  gr ass y h ill ."
          ],
      )
      augmented_varying_char = txtaugs.insert_whitespace_chars(
          self.texts, "all", 2.0, True
      )
      # Each separator is chosen independently.
      self.assertEqual(
          augmented_varying_char,
          [
              "Th e \nqu\nic\tk  br\now n \r'f ox\t' \nco\x0cul dn 't\x0b "
              "j um\x0cp \rov\ter\x0c t\x0bhe\n g\x0bre\ten\r, "
              "\rgr\x0bas\tsy\n h\x0bil\rl."
          ],
      )
  
imports: import random
  import unittest
  from augly import text
  from augly.utils import FUN_FONTS_GREEK_PATH
label_desc: Use image node_id 8 for calling the FunctionalTextUnitTest obj's underlying member method code with example usage: obj.test_insert_whitespace_chars() without return types