docs: private static int removeCommonStartCharHelper(
        List<String> lines, char charToRemove, boolean shouldRemoveMultiple) {
  
      int numCharsToRemove = 0;
  
      // Count num chars to remove.
      boolean isStillCounting = true;
      do {
        boolean areAllLinesEmpty = true;
        for (String line : lines) {
          if (line.length() == 0) {
            continue; // empty lines are okay
          }
          areAllLinesEmpty = false;
          if (line.length() <= numCharsToRemove || line.charAt(numCharsToRemove) != charToRemove) {
            isStillCounting = false;
            break;
          }
        }
        if (areAllLinesEmpty) {
          isStillCounting = false;
        }
        if (isStillCounting) {
          numCharsToRemove += 1;
        }
      } while (isStillCounting && shouldRemoveMultiple);
  
      // Perform the removal.
      if (numCharsToRemove > 0) {
        for (int i = 0; i < lines.size(); i++) {
          String line = lines.get(i);
          if (line.length() == 0) {
            continue; // don't change empty lines
          }
          lines.set(i, line.substring(numCharsToRemove));
        }
      }
  
      return numCharsToRemove;
    }