Pydantic AI 的测试支持有哪些？

from pydantic_ai.models.test import TestModel

with agent.override(model=TestModel()):
    result = agent.run_sync('Hello')
    assert isinstance(result.output, str)

from pydantic_ai.models.function import FunctionModel, ModelContext
from pydantic_ai.messages import ModelResponse, TextPart

def custom_model_function(messages: list, info: ModelContext) -> ModelResponse:
    return ModelResponse(parts=[TextPart(content='Custom response')])

with agent.override(model=FunctionModel(custom_model_function)):
    result = agent.run_sync('Any query')