pub fn maybe(
  request: a,
  value: option.Option(t),
  func: fn(a, t) -> a,
) -> a

pub fn set_bearer_token(
  request: request.Request(a),
  token: String,
) -> request.Request(a)

pub fn set_json(
  request: request.Request(a),
  data: json.Json,
) -> request.Request(BitArray)