pub unsafe extern "C" fn rocksdb_key_may_exist_cf(
db: *mut rocksdb_t,
options: *const rocksdb_readoptions_t,
column_family: *mut rocksdb_column_family_handle_t,
key: *const c_char,
key_len: usize,
value: *mut *mut c_char,
val_len: *mut usize,
timestamp: *const c_char,
timestamp_len: usize,
value_found: *mut c_uchar,
) -> c_uchar