public function modifyList ($list_name, array $items, $method, $folderPath = null) {
		// Get batch XML
		$commands = $this->prepBatch($items, $method);

                $rootFolderAttr = '';
                if($folderPath != null && $folderPath != '/') {
                    $sitePath = substr($this->spWsdl, 0, strpos($this->spWsdl, '_vti_bin'));
                    $rootFolderAttr = ' RootFolder="'.$sitePath.$list_name.'/'.$folderPath.'"';
                }

		// Wrap in CAML
		$CAML = '
		<UpdateListItems xmlns="http://schemas.microsoft.com/sharepoint/soap/">
			<listName>' . $list_name . '</listName>
			<updates>
				<Batch ListVersion="1" OnError="Continue"'.$rootFolderAttr.'>
					' . $commands . '
				</Batch>
			</updates>
		</UpdateListItems>';

		$xmlvar = new \SoapVar($CAML, XSD_ANYXML);
		$result = NULL;

		// Attempt to run operation
		try {
			$result = $this->xmlHandler($this->soapClient->UpdateListItems($xmlvar)->UpdateListItemsResult->any);
		} catch (\SoapFault $fault) {
			$this->onError($fault);
		}

		// Return a XML as nice clean Array
		return $result;
	}