fix: get all classes if inspect interface

src/test/java/jez04/structure/test/StructureHelper.java

@@ -294,9 +294,10 @@ class StructureHelper {
 					.map(Parameter::getType).map(clazz -> clazz.isArray() ? clazz.arrayType() : clazz)
 					.filter(Predicate.not(Class::isPrimitive)).map(Class::getCanonicalName)
 					.forEach(allClassesName::add);
-			allClassesName.add(foundClass.getSuperclass().getCanonicalName());
+			if(foundClass.getSuperclass() != null) {
+				allClassesName.add(foundClass.getSuperclass().getCanonicalName());
+			}
 		} catch (ClassNotFoundException e) {
-			// TODO Auto-generated catch block
 			e.printStackTrace();
 		}
 	}