code: public void setState(State state, boolean fireEvent) {
  
          boolean changed = m_state != state;
          m_state = state;
          if (changed) {
              updateStyle();
          }
          if (fireEvent) {
              ValueChangeEvent.fire(this, state);
          }
      }
docs: Sets the state of the check box and optionally fires an event.<p>
  
  @param state the new state
  @param fireEvent true if a ValueChangeEvent should be fired