code: protected function statement($text)
      {
          $text = trim($text);
          if (($pos = strpos($text, ':20:')) === false) {
              throw new \RuntimeException('Not an MT940 statement');
          }
  
          $this->statementHeader(substr($text, 0, $pos));
          return $this->statementBody(substr($text, $pos));
      }
docs: Parse a statement chunk
  
  @param string $text Statement text
  @return \Jejik\MT940\Statement
  @throws \RuntimeException if the chunk cannot be parsed