Why is default being appended to beginning of my service call?

Hi all, trying to finish my first app daemon and I’m seeing some strange behavior I haven’t seen with other service calls.

This service call is giving me

self.call_service("media_player/volume_set", entity_id = "media_player.itunes", volume_level=50)

this error:

2020-10-28 22:21:09.384063 WARNING HASS: Error calling Home Assistant service default/media_player/volume_set
2020-10-28 22:21:09.384351 WARNING HASS: Code: 400, error: 400: Bad Request

Does anyone know what the “default” is that it’s appending to the front and how I get rid of it?

As usual it’s just me being a bonehead. Volume should be expressed as a fraction of 1 rather than 0-100. So nothing weird on the app daemon side. After further reading I learned that default was the namespace and a lot of stuff about namespaces in app daemon that I probably will never use.