old_contents: from unittest import TestCase
  
  from asserts import assert_equal
  
  from htmlgen import Image
  
  from test_htmlgen.util import parse_short_tag
  
  
  class ImageTest(TestCase):
  
      def test_attributes(self):
          image = Image("my-image.png", "Alternate text")
          assert_equal("my-image.png", image.url)
          assert_equal("Alternate text", image.alternate_text)
  
      def test_attributes_default_alt(self):
          image = Image("my-image.png")
          assert_equal("", image.alternate_text)
  
      def test_with_alt(self):
          image = Image("my-image.png", "Alternate text")
          tag = parse_short_tag(str(image))
          assert_equal("img", tag.name)
          assert_equal("my-image.png", image._attributes["src"])
          assert_equal("Alternate text", image._attributes["alt"])
  
      def test_without_alt(self):
          image = Image("my-image.png")
          tag = parse_short_tag(str(image))
          assert_equal("img", tag.name)
          assert_equal("my-image.png", image._attributes["src"])
          assert_equal("", image._attributes["alt"])
  
new_contents: from unittest import TestCase
  
  from asserts import assert_equal
  
  from htmlgen import Image
  
  from test_htmlgen.util import parse_short_tag
  
  
  class ImageTest(TestCase):
  
      def test_attributes(self):
          image = Image("my-image.png", "Alternate text")
          assert_equal("my-image.png", image.url)
          assert_equal("Alternate text", image.alternate_text)
  
      def test_attributes_default_alt(self):
          image = Image("my-image.png")
          assert_equal("", image.alternate_text)
  
      def test_with_alt(self):
          image = Image("my-image.png", "Alternate text")
          tag = parse_short_tag(str(image))
          assert_equal("img", tag.name)
          assert_equal("my-image.png", image.get_attribute("src"))
          assert_equal("Alternate text", image.get_attribute("alt"))
  
      def test_without_alt(self):
          image = Image("my-image.png")
          tag = parse_short_tag(str(image))
          assert_equal("img", tag.name)
          assert_equal("my-image.png", image.get_attribute("src"))
          assert_equal("", image.get_attribute("alt"))
  
subject: Use public API in tests