code: private void createDebugLabel(int offset, Label[] labels) {
          if (labels[offset] == null) {
              readLabel(offset, labels).status |= Label.DEBUG;
          }
      }
docs: Creates a label with the Label.DEBUG flag set, if there is no already
  existing label for the given offset (otherwise does nothing). The label
  is created with a call to {@link #readLabel}.
  
  @param offset
  a bytecode offset in a method.
  @param labels
  the already created labels, indexed by their offset.