class EntityConditionGroup

class EntityConditionGroup {
    
    /**
     * The AND conjunction value.
     *
     * @var array
     */
    protected static $allowedConjunctions = [
        'AND',
        'OR',
    ];
    
    /**
     * The conjunction.
     *
     * @var string
     */
    protected $conjunction;
    
    /**
     * The members of the condition group.
     *
     * @var \Drupal\jsonapi\Query\EntityCondition[]
     */
    protected $members;
    
    /**
     * Constructs a new condition group object.
     *
     * @param string $conjunction
     *   The group conjunction to use.
     * @param array $members
     *   (optional) The group conjunction to use.
     */
    public function __construct($conjunction, array $members = []) {
        if (!in_array($conjunction, self::$allowedConjunctions)) {
            throw new \InvalidArgumentException('Allowed conjunctions: AND, OR.');
        }
        $this->conjunction = $conjunction;
        $this->members = $members;
    }
    
    /**
     * The condition group conjunction.
     *
     * @return string
     *   The condition group conjunction.
     */
    public function conjunction() {
        return $this->conjunction;
    }
    
    /**
     * The members which belong to the condition group.
     *
     * @return \Drupal\jsonapi\Query\EntityCondition[]
     *   The member conditions of this condition group.
     */
    public function members() {
        return $this->members;
    }

}