def signing_certificates(options = {})
      batches = Enumerator.new do |y|
        resp = @client.list_signing_certificates(options)
        resp.each_page do |page|
          batch = []
          page.data.certificates.each do |c|
            batch << SigningCertificate.new(
              user_name: c.user_name,
              id: c.certificate_id,
              data: c,
              client: @client
            )
          end
          y.yield(batch)
        end
      end
      SigningCertificate::Collection.new(batches)
    end
def signing_certificates(options = {})
      batches = Enumerator.new do |y|
        resp = @client.list_signing_certificates(options)
        resp.each_page do |page|
          batch = []
          page.data.certificates.each do |c|
            batch << SigningCertificate.new(
              user_name: c.user_name,
              id: c.certificate_id,
              data: c,
              client: @client
            )
          end
          y.yield(batch)
        end
      end
      SigningCertificate::Collection.new(batches)
    end
@example Request syntax with placeholder values

   signing_certificates = current_user.signing_certificates({
     user_name: "existingUserNameType",
   })
 @param [Hash] options ({})
 @option options [String] :user_name
   The name of the IAM user whose signing certificates you want to
   examine.

   This parameter allows (through its [regex pattern][1]) a string of
   characters consisting of upper and lowercase alphanumeric characters
   with no spaces. You can also include any of the following characters:
   \_+=,.@-



   [1]: http://wikipedia.org/wiki/regex
 @return [SigningCertificate::Collection]