chore: import upstream snapshot with attribution

python/ray/serve/tests/test_config_files/multi_fastapi.py

@@ -0,0 +1,28 @@
+from fastapi import FastAPI
+
+from ray import serve
+from ray.serve.handle import DeploymentHandle
+
+app1 = FastAPI()
+app2 = FastAPI()
+
+
+@serve.deployment
+@serve.ingress(app2)
+class SubModel:
+    def add(self, a: int):
+        return a + 1
+
+
+@serve.deployment
+@serve.ingress(app1)
+class Model:
+    def __init__(self, submodel: DeploymentHandle):
+        self.submodel = submodel
+
+    @app1.get("/{a}")
+    async def func(self, a: int):
+        return await self.submodel.add.remote(a)
+
+
+invalid_model = Model.bind(SubModel.bind())