pub unsafe extern "C" fn rocksdb_transaction_get_for_update(
txn: *mut rocksdb_transaction_t,
options: *const rocksdb_readoptions_t,
key: *const c_char,
klen: usize,
vlen: *mut usize,
exclusive: c_uchar,
errptr: *mut *mut c_char
) -> *mut c_char