pub fn decode(
  promise: promise.Promise(Result(dynamic.Dynamic, String)),
  decoder: decode.Decoder(t),
) -> promise.Promise(Result(t, String))

pub fn invoke(command: String) -> CommandBuilder

pub fn send(
  builder: CommandBuilder,
) -> promise.Promise(Result(dynamic.Dynamic, String))

pub fn with(
  builder: CommandBuilder,
  key: String,
  value: argument.Argument,
) -> CommandBuilder