@Override
			public void hierarchyChanged(HierarchyEvent e) {
				long changeFlags = e.getChangeFlags();
				if (HierarchyEvent.DISPLAYABILITY_CHANGED == (changeFlags &
					HierarchyEvent.DISPLAYABILITY_CHANGED)) {

					// check for the first time we are put together
					if (splitPane.isDisplayable()) {
						SwingUtilities.invokeLater(() -> splitPane.setDividerLocation(.5));
						splitPane.removeHierarchyListener(this);
					}
				}
			}
A variable used to restrict open-ended operations, like expanding all nodes or filtering.
Ghidra/Features/DecompilerDependent/src/main/java/ghidra/app/plugin/core/decompiler/taint/TaintSliceTreeProvider.java