@type t() :: %ExBifrost.Model.CohereChatV2200ResponseDeltaUsage{
  billed_units:
    ExBifrost.Model.CohereChatV2200ResponseDeltaUsageBilledUnits.t() | nil,
  cached_tokens: integer() | nil,
  tokens: ExBifrost.Model.AnthropicCreateComplete200ResponseUsage.t() | nil
}