@type t() :: %Gemini.Types.CachedContentUsageMetadata{
  audio_duration_seconds: (integer() | nil) | nil,
  cached_content_token_count: (integer() | nil) | nil,
  image_count: (integer() | nil) | nil,
  text_count: (integer() | nil) | nil,
  total_token_count: (integer() | nil) | nil,
  video_duration_seconds: (integer() | nil) | nil
}