/**
  * Register a binding if it hasn't already been registered.
  *
  * @param string $abstract
  * @param \Closure|string|null $concrete
  * @param bool $shared
  * @return void 
  * @static 
  */
 public static function bindIf($abstract, $concrete = null, $shared = false)
 {
     //Method inherited from \Illuminate\Container\Container
     \Laravel\Lumen\Application::bindIf($abstract, $concrete, $shared);
 }