@Nullable
  @Override
  public Element getState() {
    Element state = XmlSerializer.serialize(this);
    if (state == null) {
      state = new Element("state");
    }

    if (!Arrays.equals(DEFAULT_STEPPING_FILTERS, mySteppingFilters)) {
      DebuggerUtilsEx.writeFilters(state, "filter", mySteppingFilters);
    }

    for (ContentState eachState : myContentStates.values()) {
      final Element content = new Element("content");
      if (eachState.write(content)) {
        state.addContent(content);
      }
    }
    return state;
  }
@Nullable
  @Override
  public Element getState()