gistfile1.rb

    def self.mounted_path_for_engine(engine_klass)
      route = ::Rails.application.routes.routes.detect do |route|
        route.instance_variable_get("@app").instance_variable_get("@app") == engine_klass
      end

      route && route.instance_variable_get("@path_formatter").instance_variable_get("@parts").join("")
    end