xml.push_deferred_attribute('xmlns:dc': 'http://purl.org/dc/elements/1.1/',
                            'xmlns:oai-id': 'http://www.openarchives.org/OAI/2.0/oai-identifier',
                            'xmlns': 'http://www.openarchives.org/OAI/2.0/',
                            'xmlns:etd_ms': 'http://www.ndltd.org/standards/metadata/etdms/1.0/',
                            'xmlns:atom': 'http://www.w3.org/2005/Atom',
                            'xmlns:rdfs': 'http://www.w3.org/2000/01/rdf-schema#',
                            'xmlns:rdf': 'http://www.w3.org/1999/02/22-rdf-syntax-ns#',
                            'xmlns:dcterms': 'http://purl.org/dc/terms/',
                            'xmlns:oreatom': 'http://www.openarchives.org/ore/atom/',
                            'xmlns:oai_dc': 'http://www.openarchives.org/OAI/2.0/oai_dc/',
                            'xmlns:xsi': 'http://www.w3.org/2001/XMLSchema-instance',
                            'xsi:schemaLocation': 'http://www.openarchives.org/OAI/2.0/ '\
                            'http://www.openarchives.org/OAI/2.0/OAI-PMH.xsd '\
                            'http://www.openarchives.org/OAI/2.0/oai-identifier '\
                            'http://www.openarchives.org/OAI/2.0/oai-identifier.xsd '\
                            'http://www.openarchives.org/OAI/2.0/oai_dc/ '\
                            'http://www.openarchives.org/OAI/2.0/oai_dc.xsd '\
                            'http://www.ndltd.org/standards/metadata/etdms/1.0/ '\
                            'http://www.ndltd.org/standards/metadata/etdms/1-0/etdms.xsd '\
                            'http://www.w3.org/2005/Atom')

xml.tag!('request', parameters, 'https://era.library.ualberta.ca/oai')
xml.ListIdentifiers do
  identifiers.each do |identifier, date, sets|
    xml.tag!('header') do
      xml.identifier 'oai:era.library.ualberta.ca:' + identifier
      xml.datestamp date.utc.xmlschema
      sets.each do |set|
        xml.setSpec set.tr('/', ':')
      end
    end
  end
  resumption_token(xml_object: xml, complete_list_size: complete_list_size, cursor: cursor,
                   resumption_token: resumption_token, last_page: last_page,
                   resumption_token_provided: resumption_token_provided)
end
