Add coverage

tools/telemetry/third_party/coverage/tests/test_backward.py

+# Licensed under the Apache License: http://www.apache.org/licenses/LICENSE-2.0
+# For details: https://bitbucket.org/ned/coveragepy/src/default/NOTICE.txt
+
+"""Tests that our version shims in backward.py are working."""
+
+from coverage.backunittest import TestCase
+from coverage.backward import iitems, binary_bytes, byte_to_int, bytes_to_ints
+
+
+class BackwardTest(TestCase):
+    """Tests of things from backward.py."""
+
+    def test_iitems(self):
+        d = {'a': 1, 'b': 2, 'c': 3}
+        items = [('a', 1), ('b', 2), ('c', 3)]
+        self.assertCountEqual(list(iitems(d)), items)
+
+    def test_binary_bytes(self):
+        byte_values = [0, 255, 17, 23, 42, 57]
+        bb = binary_bytes(byte_values)
+        self.assertEqual(len(bb), len(byte_values))
+        self.assertEqual(byte_values, list(bytes_to_ints(bb)))
+        self.assertEqual(byte_values, [byte_to_int(b) for b in bb])