code: public static void replaceWord(StringBuilder input, String word, String replace) {
          replaceWord(input, word, replace, false);
      }
docs: Replace all occurrences of word by replace in the input. The replacement happens only if the word to replace is
  separated from others words, that is, it's not part of a word. The implementation is that the previous and next
  characters of the word must be a {@link Character#isLetterOrDigit(char)} char.
  @param input text where the replacements take place
  @param word the word to replace
  @param replace the new text to use