code: protected function contraAccount(array $lines)
      {
          $number = $this->contraAccountNumber($lines);
          $name = $this->contraAccountName($lines);
  
          if ($name || $number) {
              $contraAccount = $this->reader->createContraAccount($number);
              $contraAccount->setNumber($number)
                            ->setName($name);
  
              return $contraAccount;
          }
  
          return null;
      }
docs: Get the contra account from a transaction
  
  @param array $lines The transaction text at offset 0 and the description at offset 1
  @return \Jejik\MT940\AccountInterface|null