Function librocksdb_sys::rocksdb_optimistictransaction_begin

pub unsafe extern "C" fn rocksdb_optimistictransaction_begin(
    otxn_db: *mut rocksdb_optimistictransactiondb_t, 
    write_options: *const rocksdb_writeoptions_t, 
    otxn_options: *const rocksdb_optimistictransaction_options_t, 
    old_txn: *mut rocksdb_transaction_t
) -> *mut rocksdb_transaction_t