# File test/test_rrdtool.rb, line 77
  def test_first
    # first and last should raise an exception without an RRD file
    assert_raise RRDtoolError do
      @r.first 0
    end
    create_file
    (0..1).each do |i|
      f = @r.first i
      assert_not_nil f
      assert f > 0
    end
    assert_raise RRDtoolError do
      f2 = @r.first 2
    end
  end