chore: import upstream snapshot with attribution

contributing/samples/workflows/loop_self/agent.py

@@ -0,0 +1,45 @@
+# 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 google.adk import Event
+from google.adk import Workflow
+
+
+def validate_input(node_input: str):
+  parsed_number = int(node_input)
+  if parsed_number > 10 or parsed_number < 0:
+    yield Event(message='Please provide a number between 0 and 10.')
+    raise ValueError('Invalid input.')
+  else:
+    yield Event(state={'target_number': parsed_number})
+
+
+def guess_number(target_number: int):
+  guess = random.randint(0, 10)
+  yield Event(message=f'Guessing {guess}...')
+  if guess == target_number:
+    yield Event(message='Correct!')
+  else:
+    yield Event(route='guessed_wrong')
+
+
+root_agent = Workflow(
+    name='root_agent',
+    edges=[
+        ('START', validate_input, guess_number),
+        (guess_number, {'guessed_wrong': guess_number}),
+    ],
+)