public void clearUnassignedBytecodeMappingData() {
    myBytecodeOffsetMapping.keySet().removeIf(key -> key.myClass == null);
  }
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