PK_ERROR_code_t    PK_PMARK_ask_following
(
--- received arguments ---
PK_PMARK_t         pmark,        --- a pmark

--- returned arguments ---
int         *const n_following,  --- number of following pmarks
PK_PMARK_t **const following     --- following pmarks (optional)
)


This function returns the pmarks following the given one, i.e. its alternative
future pmarks in the pmark graph.


Specific Errors:
    PK_ERROR_rollback_not_started  Partitioned rollback is not active


The output array following is optional. If it is set to NULL, the function
will only compute the number of following pmarks of the pmark.