public TextBuffer prepend(String s) {
    myStringBuilder.insert(0, s);
    shiftMapping(s.length());
    return this;
  }
If the current group is applied, add a newline here. Otherwise, add the argument.
If {@code dedent} is true, the extra indent from this group is unapplied from this point on.
src/org/jetbrains/java/decompiler/util/TextBuffer.java