public function get($className, $ctorArgs = [], $useCache = true) {
		if (!$useCache) {
			return $this->instantiate($className, $ctorArgs);
		}

		if (!array_key_exists($className, $this->instances)) {
			$instance = $this->instantiate($className, $ctorArgs);
		  $this->instances[$className] = $instance;
		}
		return $this->instances[$className];
	}