Listing Stablecoin conversions

[finoptimal-dev]

https://github.com/danpaquin/coinbasepro-python/blob/5658b2212b0fe39dde18b792f34aeaf81dda6640/cbpro/authenticated_client.py#L177

Is there a way to access (e.g. with an undocumented GET request) conversions already done? I'm trying to reconstruct the current balance of USDT, e.g., and I don't believe conversions from USDT to USD are appearing in the results of any endpoints.