test(client): add exponential backoff retry delay and retryable HTTP status code specs

tests/wave7_exponential_backoff_test.py

@@ -0,0 +1,27 @@
+import unittest
+
+class TestWave7SDKExponentialBackoff(unittest.TestCase):
+    def test_exponential_backoff_delay_calculation(self):
+        base_delay = 1.0
+        max_delay = 16.0
+        factor = 2.0
+
+        def calculate_delay(attempt):
+            return min(max_delay, base_delay * (factor ** attempt))
+
+        self.assertEqual(calculate_delay(0), 1.0)
+        self.assertEqual(calculate_delay(1), 2.0)
+        self.assertEqual(calculate_delay(2), 4.0)
+        self.assertEqual(calculate_delay(3), 8.0)
+        self.assertEqual(calculate_delay(4), 16.0)
+        self.assertEqual(calculate_delay(5), 16.0)
+
+    def test_http_retryable_status_codes(self):
+        retryable_codes = {429, 500, 502, 503, 504}
+        self.assertTrue(429 in retryable_codes)
+        self.assertTrue(503 in retryable_codes)
+        self.assertFalse(400 in retryable_codes)
+        self.assertFalse(404 in retryable_codes)
+
+if __name__ == '__main__':
+    unittest.main()