module ActionController::Helpers::ClassMethods

instead when using +capture+.
using {helper}[rdoc-ref:AbstractController::Helpers::ClassMethods#helper]
This may cause incorrect behavior with capture methods. Consider
Note that the proxy is rendered under a different view context.

Provides a proxy to access helper methods from outside the view.

def helpers
  @helper_proxy ||= begin
    proxy = ActionView::Base.empty
    proxy.config = config.inheritable_copy
    proxy.extend(_helpers)
  end
end