pub type XWalCheckpointFn = unsafe extern "C" fn(wal: *mut Wal, db: *mut sqlite3, emode: c_int, busy_handler: Option<unsafe extern "C" fn(busy_param: *mut c_void) -> c_int>, busy_arg: *mut c_void, sync_flags: c_int, n_buf: c_int, z_buf: *mut u8, frames_in_wal: *mut c_int, backfilled_frames: *mut c_int) -> c_int;