Function gio_sys::g_file_load_partial_contents_async

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