code: public function getMessagesAndVersions()
      {
          if (empty($this->messagesAndVersions)) {
              $this->messagesAndVersions = WsdlAnalyser::loadMessagesAndVersions($this->params->wsdl);
          }
  
          return $this->messagesAndVersions;
      }
docs: Extract the Messages and versions from the loaded WSDL file.
  
  Result is an associative array: keys are message names, values are versions.
  
  @return array