private boolean isValidSelection(ActionContext context) {
		Object contextObject = context.getContextObject();
		GTree gTree = (GTree) contextObject;
		if (gTree.getSelectionPaths().length != 1) {
			return false;
		}

		TreePath path = gTree.getSelectionPath();
		if (path == null) {
			return false;
		}

		GTreeNode node = (GTreeNode) path.getLastPathComponent();
		return (node instanceof SliceNode);
	}
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