code: def _deserialize(self, value, attr, data):
          
          value = super(SanitizedUnicode, self)._deserialize(value, attr, data)
          value = fix_text(value)
  
          # NOTE: This `join` might be ineffiecient... There's a solution with a
          # large compiled regex lying around, but needs a lot of tweaking.
          value = ''.join(filter(self.is_valid_xml_char, value))
          for char in self.UNWANTED_CHARACTERS:
              value = value.replace(char, '')
          return value
docs: Deserialize sanitized string value.