Function gio_2_0_sys::g_file_load_partial_contents_async

pub unsafe extern "C" fn g_file_load_partial_contents_async(
    file: *mut GFile, 
    cancellable: *mut GCancellable, 
    read_more_callback: GFileReadMoreCallback, 
    callback: Option<GAsyncReadyCallback>, 
    user_data: gpointer
)