def METHOD_NAME(self):
    stack = self.stack
    args = stack.pop()
    func = stack[-1]
    # If the function name ends with "_persist", then assume the
    # function wants the Unpickler as the first parameter.
    func_name = func.__name__
    if func_name.endswith('_persist') or func_name.endswith('Persist'):
        value = func(self, *args)
    else:
        # Otherwise, use the existing pickle convention.
        value = func(*args)
    stack[-1] = value