new_contents: import unittest
  
  from mapbox.polyline.codec import PolylineCodec
  
  
  class PolylineCodecTestCase(unittest.TestCase):
      def setUp(self):
          self.codec = PolylineCodec()
  
      def test_decode_multiple_points(self):
          d = self.codec.decode('gu`wFnfys@???nKgE??gE?????oK????fE??fE')
          self.assertEqual(d, [
              (40.641, -8.654),
              (40.641, -8.654),
              (40.641, -8.656),
              (40.642, -8.656),
              (40.642, -8.655),
              (40.642, -8.655),
              (40.642, -8.655),
              (40.642, -8.653),
              (40.642, -8.653),
              (40.642, -8.653),
              (40.641, -8.653),
              (40.641, -8.654)
          ])
  
      def test_decode_official_example(self):
          d = self.codec.decode('_p~iF~ps|U_ulLnnqC_mqNvxq`@')
          self.assertEqual(d, [
              (38.500, -120.200),
              (40.700, -120.950),
              (43.252, -126.453)
          ])
  
      def test_decode_single_point(self):
          d = self.codec.decode('gu`wFf`ys@')
          self.assertEqual(d, [
              (40.641, -8.653)
          ])
  
      def test_encode_multiple_points(self):
          e = self.codec.encode([
              (40.641, -8.654),
              (40.641, -8.654),
              (40.641, -8.656),
              (40.642, -8.656),
              (40.642, -8.655),
              (40.642, -8.655),
              (40.642, -8.655),
              (40.642, -8.653),
              (40.642, -8.653),
              (40.642, -8.653),
              (40.641, -8.653),
              (40.641, -8.654)
          ])
          self.assertEqual(e, 'gu`wFnfys@???nKgE??gE?????oK????fE??fE')
  
      def test_encode_official_example(self):
          e = self.codec.encode([
              (38.500, -120.200),
              (40.700, -120.950),
              (43.252, -126.453)
          ])
          self.assertEqual(e, '_p~iF~ps|U_ulLnnqC_mqNvxq`@')
  
      def test_encode_single_point(self):
          e = self.codec.encode([
              (40.641, -8.653)
          ])
          self.assertEqual(e, 'gu`wFf`ys@')
  
subject: Add polyline codec tests