code: @SuppressWarnings("unchecked")
      private <T extends Assignable> Constructor<T> findConstructor(Class<T> extensionImplClass) {
          Constructor<?>[] constructors = SecurityActions.getConstructors(extensionImplClass);
          for (Constructor<?> constructor : constructors) {
              Class<?>[] parameters = constructor.getParameterTypes();
              if (parameters.length != 1) {
                  continue;
              }
              Class<?> parameter = parameters[0];
              if (Archive.class.isAssignableFrom(parameter)) {
                  return (Constructor<T>) constructor;
              }
          }
          throw new ExtensionLoadingException("No constructor with a single argument of type " + Archive.class.getName()
              + " could be found");
      }
docs: Finds a constructor with a one-argument list's element which implements {@link Archive}.
  
  @param <T>
  @param extensionImplClass
  - Implementation of {@link Assignable} with a one-argument list's element which implements
  {@link Archive}.
  @return