private void noMatch(String expr, String pattern, MapAction aMap) {
   MapResult rMap = ExprMatcher.match(expr, pattern, aMap);
   assertNull(rMap);
 }
 private MapResult match(String expr, String pattern, MapAction aMap, MapResult expected) {
   MapResult rMap = ExprMatcher.match(expr, pattern, aMap);
   assertNotNull(rMap);
   if (expected != null) assertEquals(expected, rMap);
   return rMap;
 }