code: public static <T> void register(Class<T> pluginClass, T pluginImpl) throws IllegalStateException {
  		INSTANCE.registerInternal(pluginClass, pluginImpl);
  	}
docs: Registers an implementation as a global override of any injected or default implementations.
  
  @param pluginClass The interface which is being registered.
  @param pluginImpl  The implementation of that interface which is being registered.
  @throws IllegalStateException If called more than once or if a value has already been requested.