new_contents: import unittest
  from twombly import *
  
  
  
  class TestDrawing(unittest.TestCase):
      def setUp(self):
          self.image = new_image(1200, 800)
          self.drawing = draw(self.image)
  
      def test_new_drawing(self):
          self.assertIsNotNone(self.image)
          self.assertEquals(self.image.shape[0], 800)
          self.assertEquals(self.image.shape[1], 1200)
          self.assertEquals(self.image.shape[2], 3)
          self.assertIsInstance(self.drawing, Drawing)
  
      def test_draw_line(self):
          self.drawing.set_antialias(False)
          self.drawing.set_color(255, 0, 255)
          self.drawing.move_to(10, 10)
          self.drawing.line_to(120, 80)
          self.drawing.set_line_width(10)
          self.drawing.stroke()
          self.assertEquals(self.image[11, 11][0], 255)
          self.assertEquals(self.image[79, 119][0], 255)
          self.assertEquals(self.image[79, 119][0], 255)
  
      def test_draw_rect(self):
          self.drawing.set_color(0, 255, 0)
          self.drawing.rect(150, 120, 180, 170)
          self.drawing.fill()
          self.assertEquals(self.image[150, 150][1], 255)
          self.assertEquals(self.image[150, 150][0], self.image[150, 150][2])
  
  if __name__ == '__main__':
      unittest.main()
  
subject: add some python tests