code: def test_insert_punctuation_chars(self) -> None:
      augmented_every_char = txtaugs.insert_punctuation_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_punctuation_chars(
          self.texts, "word", 1.0, False
      )
      # Each word uses a different separator; no separators around whitespace.
      self.assertEqual(
          augmented_per_word,
          [
              "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_wider_cadence = txtaugs.insert_punctuation_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_punctuation_chars(
          self.texts, "all", 2.0, True
      )
      # Each separator is chosen independently.
      self.assertEqual(
          augmented_varying_char,
          [
              "Th?e ,qu,ic!k .br,ow.n :'f.ox!' ;co...ul.dn?'t' j.um...p :ov!er' "
              "t-he, g're?en:, ;gr'as!sy, h-il;l."
          ],
      )
  
imports: import random
  import unittest
  from augly import text
  from augly.utils import FUN_FONTS_GREEK_PATH
label_desc: Use image node_id 7 for calling the FunctionalTextUnitTest obj's underlying member method code with example usage: obj.test_insert_punctuation_chars() without return types