void (JPanel panel, GridBagConstraints gc) { builders.stream().filter(b -> b.constrainsValid()).forEach(b -> b.addToPanel(panel, gc, splitColumns)); if (!expand) { gc.gridx = 0; gc.anchor = GridBagConstraints.PAGE_END; gc.fill = GridBagConstraints.BOTH; gc.weighty = 1.0; gc.insets = JBUI.insets(0); gc.gridwidth = gridWidth(); panel.add(new JPanel(), gc); } }