def extract_imgs_from_page(page)
      return Set[] if page.is_redirect?
      page.doc.search('//img[@src]').reduce(Set[]) do |result, elem|
        u = elem.attributes['src'].content
        result << page.to_absolute(URI.parse(URI.encode(u)))
      end
    end
def extract_imgs_from_page(page)
      return Set[] if page.is_redirect?
      page.doc.search('//img[@src]').reduce(Set[]) do |result, elem|
        u = elem.attributes['src'].content
        result << page.to_absolute(URI.parse(URI.encode(u)))
      end
    end
Extract imgs urls from page

 @param [Spidr::Page] an Spidr::Page object
 @return [Array] Lists of urls