Allows to get how many groups have the given user inside them.
INVOCATION METHOD: This function allows to perform an synchronous remote invocation. for the service "af_kernel::af_group::af_user_num_elements".
This function is a synchronous version for afdal_af_kernel_af_group_af_user_num_elements function.
|af_user_id ||User unique identifier to count how many group have this user included. |