fix of pinterest#549 and test added

pymemcache/client/hash.py

@@ -450,6 +450,17 @@ def replace(self, key, *args, **kwargs):
     def touch(self, key, *args, **kwargs):
         return self._run_cmd("touch", key, False, *args, **kwargs)
 
+    def stats(self, *args, **kwargs):
+        result = list()
+        for key, client in self.clients.items():
+            result.append(
+                (
+                    key,
+                    self._safely_run_func(client, client.stats, False, *args, **kwargs),
+                )
+            )
+        return result
+
     def flush_all(self, *args, **kwargs) -> None:
         for client in self.clients.values():
             self._safely_run_func(client, client.flush_all, False, *args, **kwargs)

pymemcache/test/test_client_hash.py

@@ -409,6 +409,19 @@ def test_noreply_flush(self):
         client = self.make_client()
         client.flush_all(noreply=True)
 
+    def test_stats_many_server(self):
+        client = self.make_client(
+            *[
+                [b"STAT fake_stats 1\r\n", b"END\r\n"],
+                [b"STAT fake_stats 2\r\n", b"END\r\n"],
+            ]
+        )
+        result = client.stats()
+        assert result == [
+            ("127.0.0.1:11012", {b"fake_stats": 1}),
+            ("127.0.0.1:11013", {b"fake_stats": 2}),
+        ]
+
     def test_set_many_unix(self):
         values = {"key1": "value1", "key2": "value2", "key3": "value3"}