module Roda::RodaPlugins::CustomBlockResults::RequestMethods

def unsupported_block_result(result)

to get the block result.
Try each configured custom block result, and call the related method 
def unsupported_block_result(result)
  roda_class.opts[:custom_block_results].each do |klass, meth|
    if klass === result
      result = scope.send(meth, result)
      if String === result
        return result
      else
        return
      end
    end
  end
  super
end