code: def listmetadataformats(**kwargs):
      
      cfg = current_app.config
      e_tree, e_listmetadataformats = verb(**kwargs)
  
      if 'identifier' in kwargs:
          # test if record exists
          OAIIDProvider.get(pid_value=kwargs['identifier'])
  
      for prefix, metadata in cfg.get('OAISERVER_METADATA_FORMATS', {}).items():
          e_metadataformat = SubElement(
              e_listmetadataformats, etree.QName(NS_OAIPMH, 'metadataFormat')
          )
          e_metadataprefix = SubElement(
              e_metadataformat, etree.QName(NS_OAIPMH, 'metadataPrefix')
          )
          e_metadataprefix.text = prefix
          e_schema = SubElement(
              e_metadataformat, etree.QName(NS_OAIPMH, 'schema')
          )
          e_schema.text = metadata['schema']
          e_metadataNamespace = SubElement(
              e_metadataformat, etree.QName(NS_OAIPMH, 'metadataNamespace')
          )
          e_metadataNamespace.text = metadata['namespace']
  
      return e_tree
docs: Create OAI-PMH response for ListMetadataFormats verb.