/**
  * Get Storage Revisions
  *
  * @param fromRevision - optional -
  * 		Revision Number
  *
  * @return A workspaceChanges object is returned with a list of all the file and folder revisions.
  */
 public function getStorageRevisions($fromRevision)
 {
     $urld = 'dpi/v1/storage/revisions';
     if (strlen($fromRevision) == 0) {
         $parameters = array();
     } else {
         $parameters = array('fromRevision' => $fromRevision);
     }
     $this->response = $this->restTransportInstance->sendRequest($urld, $parameters, self::HTTP_GET, $this->authToken);
     $responseBody = simplexml_load_string($this->response);
     $returnObject = new StorageChanges();
     if ($responseBody === false) {
         $errorCode = 'N/A';
         $errorMessage = 'The server has encountered an error, please try again.';
         $errorObject = new ErrorStatus($errorCode, $errorMessage);
         $returnObject->setErrorStatus($errorObject);
     } else {
         $errorStatus = $responseBody->errorStatus;
         if (empty($errorStatus)) {
             $returnObject->setCurrentUsage((string) $responseBody->currentUsage);
             $returnObject->setRevision((string) $responseBody->revision);
             $returnObject->setRevisionCount((string) $responseBody->revisionCount);
             $returnObject->setStatusDisplay((string) $responseBody->statusDisplay);
             $returnObject->setStorageQuota((string) $responseBody->storageQuota);
             $returnObject->setWorkspaceId((string) $responseBody->workspaceId);
             $files = array();
             $filesTag = (string) $responseBody->file->count();
             if (!empty($filesTag)) {
                 foreach ($responseBody->file as $currentFile) {
                     if ($currentFile->count() > 0) {
                         $file = new File();
                         $file->setCreatedOn((string) $currentFile->createdOn);
                         $file->setDeleteStatus((string) $currentFile->deleteStatus);
                         $file->setFileId((string) $currentFile->fileId);
                         $file->setFileName((string) $currentFile->fileName);
                         $file->setFolderId((string) $currentFile->folderId);
                         $file->setLastUpdatedOn((string) $currentFile->lastUpdatedOn);
                         $file->setRevision((string) $currentFile->revision);
                         array_push($files, $file);
                     }
                 }
                 $returnObject->setFiles($files);
             }
             $folders = array();
             $foldersTag = (string) $responseBody->folder->count();
             if (!empty($foldersTag)) {
                 foreach ($responseBody->folder as $currentFolder) {
                     if ($currentFolder->count() > 0) {
                         $folder = new Folder();
                         $folder->setCreatedOn((string) $currentFolder->createdOn);
                         $folder->setDeletedStatus((string) $currentFolder->deletedStatus);
                         $folder->setFolderId((string) $currentFolder->folderId);
                         $folder->setFolderType((string) $currentFolder->folderType);
                         $folder->setLastUpdatedOn((string) $currentFolder->lastUpdatedOn);
                         $folder->setRevision((string) $currentFolder->revision);
                         $folder->setShareInvitationPending((string) $currentFolder->shareInvitationPending);
                         $folder->setSize((string) $currentFolder->size);
                         $permissions = array();
                         $permissionsTag = (string) $currentFolder->permissions->count();
                         if (!empty($permissionsTag)) {
                             foreach ($currentFolder->permissions as $currentPermission) {
                                 $permission = new Permission();
                                 $permission->setWsPermissionName((string) $currentPermission->wsPermissionName);
                                 array_push($permissions, $permission);
                             }
                         }
                         $folder->setPermissions($permissions);
                         array_push($folders, $folder);
                     }
                 }
                 $returnObject->setFolders($folders);
             }
         } else {
             $errorCode = (string) $responseBody->errorStatus->code;
             $errorMessage = (string) $responseBody->errorStatus->message;
             $errorObject = new ErrorStatus($errorCode, $errorMessage);
             $returnObject->setErrorStatus($errorObject);
         }
     }
     return $returnObject;
 }