code: def _parse_value(self, el):
          
          if el.find(RDF_NS + 'Bag') is not None:
              value = []
              for li in el.findall(RDF_NS + 'Bag/' + RDF_NS + 'li'):
                  value.append(li.text)
          elif el.find(RDF_NS + 'Seq') is not None:
              value = []
              for li in el.findall(RDF_NS + 'Seq/' + RDF_NS + 'li'):
                  value.append(li.text)
          elif el.find(RDF_NS + 'Alt') is not None:
              value = {}
              for li in el.findall(RDF_NS + 'Alt/' + RDF_NS + 'li'):
                  value[li.get(XML_NS + 'lang')] = li.text
          else:
              value = el.text
          return value
docs: Extract the metadata value from an element.