def METHOD_NAME(self):
    """Get the links from snapshot ts to its immediate successor.
    Returns a dictionary; keys are the finder IDs at the given snapnum, whereas the values are
    a tuple containing the ID at the subsequent snapshot and the fraction of shared particles.
    """
    ids_this_snap = self.links['id_this']
    ids_next_snap = self.links['id_desc']
    merger_ratios = self.links['f_share']
    return list(zip(ids_this_snap, zip(ids_next_snap, merger_ratios)))