protected function _get_array_value( $key ) {
		if ( ! isset( $this->types[ $key ] ) || 'array' !== $this->types[ $key ] ) {
			return null;
		}

		$default = array_key_exists( $key, $this->defaults ) ? $this->defaults[ $key ] : [];

		// @todo Could be taken a step further to array map strval?
		return (array) $this->store->get( $key, $default );
	}