Tai.VenueAdapters.Bitmex.Accounts.accounts

You're seeing just the function accounts, go back to Tai.VenueAdapters.Bitmex.Accounts module for more information.
Link to this function

accounts(venue_id, credential_id, credentials)

Specs

accounts(venue_id(), credential_id(), credentials()) ::
  {:ok, [account()]} | {:error, shared_error_reason()}