code: static public function getStates()
      {
          return [
              static::STATE_NEW,
              static::STATE_PENDING,
              static::STATE_CAPTURED,
              static::STATE_FAILED,
              static::STATE_CANCELED,
              static::STATE_REFUNDED,
              static::STATE_AUTHORIZED,
              static::STATE_SUSPENDED,
              static::STATE_EXPIRED,
              static::STATE_UNKNOWN,
              static::STATE_OUTSTANDING,
              static::STATE_DEPOSIT,
              static::STATE_COMPLETED,
          ];
      }
docs: Returns all the states.
  
  @return array