docs: public void setOwner(ListenerOwner owner)
      {
          super.setOwner(owner);
          if (this.getOwner() != null)
          {
              if (this.getOwner().getListener(this.getClass()) != this)
                  if (((MainFieldHandler)this.getOwner().getListener(this.getClass())).getActualKeyArea() == this.getActualKeyArea())
                      this.getOwner().removeListener(this.getOwner().getListener(this.getClass()), true); // Make sure there is only one of these
          }
      }