@Deprecated
  public int countChars(char c) {
    convertToStringAndAllowDataDiscard();

    int count = 0;

    CharSequence chars = myStringBuilder.subSequence(0, myStringBuilder.length());
    for (int i = 0; i < chars.length(); i++) {
      if (chars.charAt(i) == c) {
        count++;
      }
    }

    return count;
  }
Recursive reformatting of groups.
If the group's content would take you over the specified preferred line length, then the group is applied.

- This algorithm usually ensures that if a group is applied, then all the group's parents in the tree are also
  applied. This tends to produce a nice structured output with well-placed potential newlines.
- The formatter keeps track of the offset as a result of the reformat at each character in the text buffer, and
  applies them to the bytecode offsets afterwards, so that the line number mappings don't get messed up.
src/org/jetbrains/java/decompiler/util/TextBuffer.java