code: def enqueue(url,level=0)
        url = sanitize_url(url)
  
        if (!(queued?(url)) && visit?(url))
          link = url.to_s
  
          begin
            @every_url_blocks.each { |url_block| url_block.call(url) }
  
            @every_url_like_blocks.each do |pattern,url_blocks|
              match = case pattern
                      when Regexp
                        link =~ pattern
                      else
                        (pattern == link) || (pattern == url)
                      end
  
              if match
                url_blocks.each { |url_block| url_block.call(url) }
              end
            end
          rescue Actions::Paused => action
            raise(action)
          rescue Actions::SkipLink
            return false
          rescue Actions::Action
          end
  
          @queue << url
          @levels[url] = level
          return true
        end
  
        return false
      end
docs: Enqueues a given URL for visiting, only if it passes all of the
   agent's rules for visiting a given URL.
  
   @param [URI::HTTP, String] url
     The URL to enqueue for visiting.
  
   @return [Boolean]
     Specifies whether the URL was enqueued, or ignored.