GridBagLayout: Direction of Addition (7)

   // btn3 right of btn2
   c.gridx = GridBagConstraints.RELATIVE;
   c.gridy = 1;
   gridbag.setConstraints(btn3, c);

   // btn4 below btn3
   c.gridx = 1;
   c.gridy = GridBagConstraints.RELATIVE;
   gridbag.setConstraints(btn4, c);

   // more coming ...