chore: import upstream snapshot with attribution

contributing/samples/workflows/retry/agent.py

@@ -0,0 +1,49 @@
+# Copyright 2026 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import random
+from urllib.error import HTTPError
+
+from google.adk import Context
+from google.adk import Event
+from google.adk import Workflow
+from google.adk.workflow import node
+from google.adk.workflow import RetryConfig
+
+
+@node(retry_config=RetryConfig(max_attempts=5, initial_delay=1))
+def get_weather(ctx: Context) -> str:
+  """A mock task that fails randomly."""
+
+  yield Event(message=f"Getting weather... attempt {ctx.attempt_count}")
+  if random.random() < 0.7:  # 70% chance of failure
+    raise HTTPError(
+        url="http://mock-api.example.com",
+        code=500,
+        msg="Internal Server Error",
+        hdrs={},
+        fp=None,
+    )
+
+  yield "sunny"
+
+
+def report_weather(node_input: str):
+  yield Event(message=f"The weather is {node_input}")
+
+
+root_agent = Workflow(
+    name="root_agent",
+    edges=[("START", get_weather, report_weather)],
+)