}
static List<String> checkCardinality(List<String> extendedClass) {
- if (extendedClass.size() > 1)
+ if (extendedClass.size() > 1) {
throw new IllegalArgumentException(
- "Class cannot have more than one super " + "class");
+ "Class cannot have more than one super class, found: " + extendedClass);
+ }
return extendedClass;
}