Function rpgffi::heap_beginscan_sampling

pub unsafe extern "C" fn heap_beginscan_sampling(
    relation: Relation, 
    snapshot: Snapshot, 
    nkeys: c_int, 
    key: ScanKey, 
    allow_strat: bool_, 
    allow_sync: bool_, 
    allow_pagemode: bool_
) -> HeapScanDesc