static TailFile tailFileLinewise(File file, int interval, IVF1<S> onData) {
  ret tailFileLinewise(file, interval, toVF1(onData));
}

static TailFile tailFileLinewise(File file, int interval, VF1<S> onData) {
  ret tailFile_newOnly(file, interval,
    vfAppendToLineBuffer(new LineBuffer(onData)));
}