docs: public Class<?> findOrInsert(ClassLoader classLoader, T key, Callable<Class<?>> lazy) {
          Class<?> type = find(classLoader, key);
          if (type != null) {
              return type;
          } else {
              try {
                  return insert(classLoader, key, lazy.call());
              } catch (Throwable throwable) {
                  throw new IllegalArgumentException("Could not create type", throwable);
              }
          }
      }