# File lib/rack/mount/vendor/regin/regin/expression.rb, line 67
    def dup(options = {})
      expression = super()
      expression.multiline  = options[:multiline] if options.key?(:multiline)
      expression.ignorecase = options[:ignorecase] if options.key?(:ignorecase)
      expression.extended   = options[:extended] if options.key?(:extended)
      expression
    end