@type t() :: %ExBifrost.Model.BifrostCost{
  citation_tokens_cost: number() | nil,
  input_tokens_cost: number() | nil,
  output_tokens_cost: number() | nil,
  reasoning_tokens_cost: number() | nil,
  request_cost: number() | nil,
  search_queries_cost: number() | nil,
  total_cost: number() | nil
}