/// <summary>
/// Gets a collection of Todos.
/// </summary>
/// <param name="userId">The ID of the User to get Todos for (optional)</param>
/// <returns>A collection of all available Todos</returns>
public IEnumerable <Todo> GetTodos(int?userId = null)
{
Log.Debug($"Getting Todos");
var request = _client.CreateRequest("getTodos", new { userId });
var response = _client.SendRequest <IEnumerable <Todo> >(request);
Log.Debug($"Found {response.Count()} Todos");
return(response);
}