/**
  * Function to change the visibility of a document
  *
  * @param string $document_guid - the guid of the document to change visibility
  * @param int    $visibility    - the visibility that the document has to become
  * @return bool - $the result of the change
  */
 function visibilityService($document_guid, $visibility)
 {
     $index_address = DLEApi::getSetting('index_address');
     if ($index_address == '') {
         $this->log('Index address not found');
         return false;
     }
     $soap_client = $this->initSoapClient($index_address);
     if ($soap_client == false) {
         $this->log('... Connection problem.');
         return false;
     }
     // Call the SOAP method...
     try {
         $soap_client->IndexDocument(array('documentGuid' => $document_guid, 'indexType' => $visibility));
         DLEApi::changeVisibility($document_guid, $visibility);
         return true;
     } catch (SoapFault $e) {
         $this->log('Document (' . $document_guid . ') index change. error received - Error: ' . $e->getMessage());
         return false;
     }
 }