chore: import upstream snapshot with attribution

contributing/samples/tools/hello_world_stream_fc_args/__init__.py

@@ -0,0 +1,15 @@
+# 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 . import agent

contributing/samples/tools/hello_world_stream_fc_args/agent.py

@@ -0,0 +1,65 @@
+# 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.genai import types
+
+
+def concat_number_and_string(num: int, s: str) -> str:
+  """Concatenate a number and a string.
+
+  Args:
+    num: The number to concatenate.
+    s: The string to concatenate.
+
+  Returns:
+    The concatenated string.
+  """
+  return str(num) + ': ' + s
+
+
+def write_document(document: str) -> dict[str, str]:
+  """Write a document."""
+  return {'status': 'ok'}
+
+
+root_agent = Agent(
+    model='gemini-3-pro-preview',
+    name='hello_world_stream_fc_args',
+    description='Demo agent showcasing streaming function call arguments.',
+    instruction="""
+      You are a helpful assistant.
+      You can use the `concat_number_and_string` tool to concatenate a number and a string.
+      You should always call the concat_number_and_string tool to concatenate a number and a string.
+      You should never concatenate on your own.
+
+      You can use the `write_document` tool to write a document.
+      You should always call the write_document tool to write a document.
+      You should never write a document on your own.
+    """,
+    tools=[
+        concat_number_and_string,
+        write_document,
+    ],
+    generate_content_config=types.GenerateContentConfig(
+        automatic_function_calling=types.AutomaticFunctionCallingConfig(
+            disable=True,
+        ),
+        tool_config=types.ToolConfig(
+            function_calling_config=types.FunctionCallingConfig(
+                stream_function_call_arguments=True,
+            ),
+        ),
+    ),
+)