def html?
      fetch_headers unless fetched_headers?
      response = @get_response || @head_response
      return false if fetch_failed?
      return false unless response
      return false unless response.success?
      return false unless response["content-type"]
      response["content-type"].include? "text/html"
    end
def html?
      fetch_headers unless fetched_headers?
      response = @get_response || @head_response
      return false if fetch_failed?
      return false unless response
      return false unless response.success?
      return false unless response["content-type"]
      response["content-type"].include? "text/html"
    end
Whether the target URI seems to return HTML

 @return [Bool]