Fix: don't hardcode client class name. (#555)

Signed-off-by: dblock <[email protected]>

test_opensearchpy/test_client/test_plugins/test_plugins_client.py

@@ -0,0 +1,24 @@
+# -*- coding: utf-8 -*-
+# SPDX-License-Identifier: Apache-2.0
+#
+# The OpenSearch Contributors require contributions made to
+# this file be licensed under the Apache-2.0 license or a
+# compatible open source license.
+#
+# Modifications Copyright OpenSearch Contributors. See
+# GitHub history for details.
+
+from opensearchpy.client import OpenSearch
+
+from ...test_cases import TestCase
+
+
+class TestPluginsClient(TestCase):
+    def test_plugins_client(self):
+        with self.assertWarns(Warning) as w:
+            client = OpenSearch()
+            client.plugins.__init__(client)  # double-init
+            self.assertEqual(
+                str(w.warnings[0].message),
+                "Cannot load `alerting` directly to OpenSearch as it already exists. Use `OpenSearch.plugin.alerting` instead.",
+            )