def case_from_case_update(cls, case_update, xformdoc):
"""
Create a case object from a case update object.
"""
assert not is_deprecation(xformdoc) # you should never be able to create a case from a deleted update
case = CommCareCase()
case._id = case_update.id
case.modified_on = parsing.string_to_utc_datetime(case_update.modified_on_str) \
if case_update.modified_on_str else datetime.utcnow()
# apply initial updates, if present
ActionsUpdateStrategy(case).update_from_case_update(case_update, xformdoc)
return case
