protected static void appendText(@Nullable PsiElement stub, int indentLevel, @NotNull StringBuilder buffer, @NotNull String separator) {
    if (stub == null) return;
    int pos = buffer.length();
    ((ClsElementImpl)stub).appendMirrorText(indentLevel, buffer);
    if (buffer.length() != pos) {
      if (Strings.areSameInstance(separator, NEXT_LINE)) {
        goNextLine(indentLevel, buffer);
      }
      else {
        buffer.append(separator);
      }
    }
  }
protected static void appendText(@Nullable PsiElement stub, int indentLevel, @NotNull StringBuilder buffer, @NotNull String separator)