@type t() :: %Copilot.Types.MessageOptions{
  attachments: [map()] | nil,
  image_options: Copilot.Types.image_options() | nil,
  mode: String.t() | nil,
  prompt: String.t(),
  request_headers: %{optional(String.t()) => String.t()} | nil,
  response_format: Copilot.Types.response_format() | nil
}