private void assertIntersection(String expected, String... types) {
   Set<JetType> typesToIntersect = new LinkedHashSet<JetType>();
   for (String type : types) {
     typesToIntersect.add(makeType(type));
   }
   JetType result = TypeUtils.intersect(JetTypeChecker.DEFAULT, typesToIntersect);
   //        assertNotNull("Intersection is null for " + typesToIntersect, result);
   assertEquals(makeType(expected), result);
 }
 private void assertSupertypes(String typeStr, String... supertypeStrs) {
   Set<JetType> allSupertypes = TypeUtils.getAllSupertypes(makeType(scopeWithImports, typeStr));
   Set<JetType> expected = Sets.newHashSet();
   for (String supertypeStr : supertypeStrs) {
     JetType supertype = makeType(scopeWithImports, supertypeStr);
     expected.add(supertype);
   }
   assertEquals(expected, allSupertypes);
 }