public void track(TableOperations ops) {
    Preconditions.checkArgument(null != ops, "Invalid table ops: null");
    tracker.put(ops, ops.io());
  }
@SuppressWarnings("resource")
  @Test
  public void nullTableOps() {
    assertThatThrownBy(() -> new FileIOTracker().track(null))
        .isInstanceOf(IllegalArgumentException.class)
        .hasMessage("Invalid table ops: null");
  }