Switch _process_fields() from private to protected
diff --git a/system/database/drivers/mysqli/mysqli_forge.php b/system/database/drivers/mysqli/mysqli_forge.php
index 319c6fd..7de0361 100644
--- a/system/database/drivers/mysqli/mysqli_forge.php
+++ b/system/database/drivers/mysqli/mysqli_forge.php
@@ -66,7 +66,7 @@
 	 * @param	mixed	the fields
 	 * @return	string
 	 */
-	private function _process_fields($fields)
+	public function _process_fields($fields)
 	{
 		$current_field_count = 0;
 		$sql = '';