normalize_requirements!

# File actionpack/lib/action_dispatch/routing/mapper.rb, line 120
          def normalize_requirements!
            constraints.each do |key, requirement|
              next unless segment_keys.include?(key) || key == :controller
              verify_regexp_requirement(requirement) if requirement.is_a?(Regexp)
              @requirements[key] = requirement
            end

            if options[:format] == true
              @requirements[:format] ||= /.+/
            elsif Regexp === options[:format]
              @requirements[:format] = options[:format]
            elsif String === options[:format]
              @requirements[:format] = Regexp.compile(options[:format])
            end
          end