Updates existing CompanyUsers, including submitted Address and UserEmployment child objects (to be modified, not added or removed). Additionally you may optionally submit a list of UserEmployment.EmploymentBalanceConfiguration objects, which will then replace all existing records of that type. Provide null values (not empty lists) to leave child objects unmodified. Note also that the convenience fields UserLanguageId and UserIdentityNumber, which really belong to the User object in the hiarchy, may be updated this way. Finally, notice that users with the Employee role can only update their own CompanyUser object, and NOT the attached UserEmployment objects.