def Validate(self, value, key):
    if isinstance(value, self.ParsedMethod):
      return value
    else:
      return self.ParsedMethod(value, key)
Folder for Static Pages add
dataset/ETHPy150Open AppScale/appscale/AppServer/google/appengine/ext/bulkload/bulkloader_parser.py/EvaluatedCallable.Validate--crossover with--dataset/ETHPy150Open treeio/treeio/treeio/core/administration/views.py/pagefolder_add