code: def xsd_error_log_string(xsd_error_log):
      
      ret = []
      for error in xsd_error_log:
          ret.append(
              "ERROR ON LINE {}: {}".format(error.line, error.message.encode("utf-8"))
          )
      return "\n".join(ret)
docs: Return a human-readable string representation of the error log
      returned by lxml's XMLSchema validator.