sses with the stored data.
	 */
	protected function populate() {
		$combined = $this->retrieve();

		foreach ( $this->types as $key => $type ) {
			if ( isset( $combined[ $key ] ) ) {
				$type->merge( $combined[ $key ] );
			}
		}
	}

	/**
	 * Retrieve stored user favorites types.
	 *
	 * @return mixed|false
	 */
	protected function retrieve() {
		return get_user_option( static::OPTION_NAME );
	}

	/**
	 * Update all changes to user favorites type.
	 *
	 * @return int|bool
	 */
	protected function store() {
		return update_user_option( get_current_user_id(), static::OPTION_NAME, $this->combined() );
	}

	/**
	 * Throw action doesn't exist exception.
	 *
	 * @param string $action
	 */
	public function action_doesnt_exists( $action ) {
		throw new \InvalidArgumentException( sprintf(
			"Action '%s' to apply on favorites doesn't exists",
			$action
		) );
	}
}