File size of BIM 360 file

After about 2 hours of culling the web I finally found it. I get a warning though with the code I wrote. Do you have any Idea?

http://www.revitapidocs.com/2016/93287b85-2c12-ff55-177e-2a419fa893df.htm

Warning: IronPythonEvaluator.EvaluateIronPythonScript operation failed.
Traceback (most recent call last):
File “”, line 15, in
TypeError: Guid is not callable

import clr


clr.AddReference("RevitAPI")
from Autodesk.Revit.DB import *


clr.AddReference("RevitServices")
import RevitServices
from RevitServices.Persistence import DocumentManager
from RevitServices.Transactions import TransactionManager

doc = DocumentManager.Instance.CurrentDBDocument

doc.WorksharingCentralGUID()

OUT = doc

Some extra references.