func TestStylePrinter(t *testing.T) {
su := []*trees.Style{styles.Width(styles.Px(200))}
res := trees.SimpleStyleWriter.Print(su)
tests.StrictExpect(t, expectedStyle, res)
}
func TestAttrPrinter(t *testing.T) {
attr := []*trees.Attribute{&trees.Attribute{Name: "data-fax", Value: "butler"}}
res := trees.SimpleAttrWriter.Print(attr)
tests.StrictExpect(t, expectedAttr, res)
}