chore: import upstream snapshot with attribution

contributing/samples/tools/long_running_functions/agent.py

@@ -0,0 +1,44 @@
+# 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 google.adk import Agent
+from google.adk.tools.long_running_tool import LongRunningFunctionTool
+
+
+def export_data(export_type: str) -> dict[str, str]:
+  """Exports user data.
+
+  Args:
+      export_type: The type of data to export (e.g., 'csv', 'json').
+
+  Returns:
+      A dict with the status.
+  """
+  # In a real application, this would kick off a background job.
+  # Here we just return a status.
+  return {
+      "status": "in-progress",
+      "progress": "0%",
+      "message": f"Exporting {export_type} data. This may take some time.",
+  }
+
+
+root_agent = Agent(
+    name="long_running_functions",
+    instruction="""
+    You are an assistant that can export user data.
+    When the user asks to export data, call the `export_data` tool.
+    """,
+    tools=[LongRunningFunctionTool(func=export_data)],
+)