text: from spriter.sprite import Sprite, DefaultImageDoesNotExist
  from PIL import Image
  import os
  import unittest
  
  
  class Test(unittest.TestCase):
  
      def setUp(self):
          self.paths = ["tests/fixtures/sad.png"]
  
      def test_error_when_default_path_is_not_a_str(self):
          self.assertRaises(TypeError,
                            Sprite,
                            self.paths, default_path=1)
  
      def test_error_when_default_path_is_set_but_does_not_exists(self):
          self.assertRaises(DefaultImageDoesNotExist,
                            Sprite,
                            self.paths, default_path="ERROR")
  
      def test_write_a_default_image_when_some_path_does_not_exist(self):
          self.paths.append("tests/ERROR.png")
          default_path = os.getcwd() + "/tests/fixtures/default.png"
          sprite = Sprite(self.paths, default_path=default_path)
          sprite.gen_image()
          path = sprite.do_write_image()
          css = sprite.get_css()
          self.assertIn(".sprite.serror", css)
          sprite_img = Image.open(path)
          compare = Image.open(os.getcwd() + "/tests/fixtures/with_default.png")
          #This assert the default image is in the sprite
          self.assertEquals(sprite_img.histogram(), compare.histogram())
  