code: def _parse_string_el(el):
      
      value = str(el)
      el_type = el.attributes().get('xsi:type')
      if el_type and el_type.value == 'xsd:base64Binary':
          value = base64.b64decode(value)
          if not PY2:
              value = value.decode('utf-8', errors='replace')
      value = _uc(value)
      return value
docs: read a string element, maybe encoded in base64