dev#13786 add mkdir to Class_Testing_FileSystem

library/Class/Testing/FileSystem.php

@@ -23,7 +23,7 @@ class Class_Testing_FileSystem {
 	protected $_known_functions = ['rmdir', 'unlink', 'fopen', 'fseek', 'fgets',
 																 'filesize', 'fclose', 'ftell', 'fread', 'feof',
 																 'getcwd', 'file_exists', 'scandir', 'is_dir',
-																 'opendir', 'readdir', 'closedir'];
+																 'opendir', 'readdir', 'closedir', 'mkdir'];
 	
 	public function __call($name, $args) {
 		if (!in_array($name, $this->_known_functions))