defmodule FunctionInvoker do
  def invoke(server, module, function, args) do
    server |> GenServer.call({:call, module, function, args})
  end

  def init([]) do
    {:ok, []}
  end

  def handle_call({:call, module, function, args}, _from, state) do
    {:reply, apply(module, function, args), state}
  end
end