# File test/test_rrdtool.rb, line 151
  def test_update
    create_file
    # first, test the simple update case (now)
    @r.update "a:b", ["N:0:0"]
    assert_in_delta Time.now.to_i, @r.last, 1
    # next, create a bunch of data entries
    create_data
    l = @r.last
    @r.update "a:b", ["#{l+1}:0:0", "#{l+2}:1:1"]
    assert_equal @r.last, l+2
  end