Makes the fastapi async example more robust

When you use `/docs` to create the request, it does
not pass in an empty dict, so making sure the path
does not break.

examples/async/async_module.py

@@ -1,11 +1,19 @@
 import asyncio
+import json
+import logging
 
 import aiohttp
 import fastapi
 
+logger = logging.getLogger(__name__)
+
 
 async def request_raw(request: fastapi.Request) -> dict:
-    return await request.json()
+    try:
+        return await request.json()
+    except json.JSONDecodeError as e:
+        logger.warning(f"Unable to get JSON from request. Error is:\n{e}")
+        return {}
 
 
 def foo(request_raw: dict) -> str:

examples/async/fastapi_example.py

@@ -12,3 +12,10 @@ async def call(request: fastapi.Request) -> dict:
     dr = h_async.AsyncDriver({}, async_module)
     input_data = {"request": request}
     return await dr.raw_execute(["pipeline"], inputs=input_data)
+
+
+if __name__ == "__main__":
+    # If you run this as a script, then the app will be started on localhost:8000
+    import uvicorn
+
+    uvicorn.run(app, host="0.0.0.0", port=8000)