func TestDo(t *testing.T) {
	var err error
	writer := io_mock.NewWriter()
	err = do(writer, "/tmp/per_hour_test.db")
	err = AssertThat(err, NilValue())
	if err != nil {
		t.Fatal(err)
	}
}
func TestPrintEntries(t *testing.T) {
	var err error
	writer := io_mock.NewWriter()
	entries := []stats_entry.Entry{stats_entry.Entry{Id: 1, Timestamp: 0, Value: 100}, stats_entry.Entry{Id: 1, Timestamp: 0 + int64(time.Hour), Value: 200}}
	err = printEntries(writer, entries)
	if err = AssertThat(err, NilValue()); err != nil {
		t.Fatal(err)
	}
	if err = AssertThat(writer.Content(), NotNilValue()); err != nil {
		t.Fatal(err)
	}
	if err = AssertThat(string(writer.Content()), Is(fmt.Sprintf("%s          200          100       100.00/h\n", time.Unix(0, int64(time.Hour)).Format("2006-01-02 15:04:05")))); err != nil {
		t.Fatal(err)
	}

}