Function ostree_sys::ostree_repo_write_metadata_async

pub unsafe extern "C" fn ostree_repo_write_metadata_async(
    self_: *mut OstreeRepo, 
    objtype: OstreeObjectType, 
    expected_checksum: *const c_char, 
    object: *mut GVariant, 
    cancellable: *mut GCancellable, 
    callback: GAsyncReadyCallback, 
    user_data: gpointer
)