code: public function unmarshal($documentOrSource)
      {
          if ($documentOrSource instanceof Document) {
              return $this->doUnmarshal($documentOrSource->getData());
          }
  
          return $this->doUnmarshal($documentOrSource);
      }
docs: @param Document|array $documentOrSource Document object or source array
  
  @return Message
  
  @throws \Exception
  @throws GdbotsPbjException