class Server

Connects a listener to a stream of usage gain setting changes

for `usage` on the device identified by `device_token`. Usage

Gain is not set directly by any client; it is a translation of

the usage volume setting for each device, summed with active

muting/ducking gain adjustments.

Devices may map the same volume level to different dbfs, so

a `device_unique_id` is needed to identify the device.

`AudioDeviceEnumerator` provides programmatic access to devices

and their unique ids if it is necessary for a client to select

an id at runtime.

Connects a listener to a stream of usage gain setting changes

for `usage` on the device identified by `device_token`. Usage

Gain is not set directly by any client; it is a translation of

the usage volume setting for each device, summed with active

muting/ducking gain adjustments.

Devices may map the same volume level to different dbfs, so

a `device_unique_id` is needed to identify the device.

`AudioDeviceEnumerator` provides programmatic access to devices

and their unique ids if it is necessary for a client to select

an id at runtime.

|bind_handler| returns a handler that binds incoming connections to this

server implementation.

The returned handler borrows the server instance.

The server must outlive the provided |dispatcher|. Only after

the dispatcher is shutdown will it be safe to destroy the servers.

The server should not be moved.