def subscribe_to_email_subscription_url_for(subscription, params = {})
      options = params.dup
      options.delete(:devise_default_routes) ?
        send("subscribe_to_email_#{routing_scope(options)}subscription_url", subscription, options) :
        send("subscribe_to_email_#{routing_scope(options)}#{subscription.target.to_resource_name}_subscription_url", subscription.target, subscription, options)
    end
def subscribe_to_email_subscription_url_for(subscription, params = {})
      options = params.dup
      options.delete(:devise_default_routes) ?
        send("subscribe_to_email_#{routing_scope(options)}subscription_url", subscription, options) :
        send("subscribe_to_email_#{routing_scope(options)}#{subscription.target.to_resource_name}_subscription_url", subscription.target, subscription, options)
    end
Returns subscribe_to_email_subscription_url for the target of specified subscription

 @param [Subscription] subscription Subscription instance
 @param [Hash] params Request parameters
 @return [String] subscription_url for the subscription
 @todo Needs any other better implementation