@Test
public void testEmptyParseTreesAreEqual() {
Comparator<Node> comparator = new NodeComparator(new byte[] {});
Node empty = new ColumnVisibility().getParseTree();
assertEquals(0, comparator.compare(empty, parse("")));
}
@Test
public void testParseTreesOrdering() {
byte[] expression = "(b&c&d)|((a|m)&y&z)|(e&f)".getBytes(Constants.UTF8);