code: private JComponent createControls()
      {
          JPanel controls = new JPanel(new FlowLayout(FlowLayout.RIGHT));
          JButton gcButton = new JButton("Request GC");
          gcButton.setToolTipText("Perform garbage collection (the JVM may ignore this request).");
          gcButton.addActionListener(new ActionListener()
          {
              public void actionPerformed(ActionEvent ev)
              {
                  memoryBean.gc();
              }
          });
          controls.add(gcButton);
          return controls;
      }
docs: Creates the GUI controls for toggling graph display options.
  @return A component that can be added to the main panel.