chore: import upstream snapshot with attribution

contributing/samples/workflows/route/agent.py

@@ -0,0 +1,77 @@
+# 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.
+
+from typing import Literal
+
+from google.adk import Agent
+from google.adk import Event
+from google.adk import Workflow
+from pydantic import BaseModel
+
+
+class InputCategory(BaseModel):
+  category: Literal["question", "statement", "other"]
+
+
+def process_input(node_input: str):
+  return Event(state={"input": node_input})
+
+
+classify_input = Agent(
+    name="classify_input",
+    instruction=(
+        "Based on this input, decide which category it belongs to: {input}"
+    ),
+    output_schema=InputCategory,
+    output_key="category",
+)
+
+
+def route_on_category(category: InputCategory):
+  """Yields an Event with a specific route based on the classification."""
+  yield Event(route=category.category)
+
+
+answer_question = Agent(
+    name="answer_question",
+    instruction="""Answer the question: {input}""",
+)
+
+
+comment_on_statement = Agent(
+    name="comment_on_statement",
+    instruction="""Comment on the statement: {input}""",
+)
+
+
+def handle_other():
+  yield Event(
+      message="Sorry I can only anwer questions or comment on statements."
+  )
+
+
+root_agent = Workflow(
+    name="root_agent",
+    edges=[
+        ("START", process_input, classify_input, route_on_category),
+        (
+            route_on_category,
+            {
+                "question": answer_question,
+                "statement": comment_on_statement,
+                "other": handle_other,
+            },
+        ),
+    ],
+)