get_class

# File actionpack/lib/action_dispatch/middleware/stack.rb, line 112
    def get_class(klass)
      if klass.is_a?(String) || klass.is_a?(Symbol)
        classcache = ActiveSupport::Dependencies::Reference
        converted_klass = classcache[klass.to_s]
        ActiveSupport::Deprecation.warn Passing strings or symbols to the middleware builder is deprecated, please changethem to actual class references.  For example:  "#{klass}" => #{converted_klass}
        converted_klass
      else
        klass
      end
    end