code: def emit(self, record):
          
          if record.levelno == logging.DEBUG and self.is_tty() and isinstance(record.args, dict):
              for key, value in record.args.items():
                  if not key.startswith('xml_'):
                      continue
                  if not isinstance(value, bytes):
                      continue
                  if not is_xml(value):
                      continue
                  try:
                      if PY2:
                          record.args[key] = self.highlight_xml(self.prettify_xml(value)).encode('utf-8')
                      else:
                          record.args[key] = self.highlight_xml(self.prettify_xml(value))
                  except Exception as e:
                      # Something bad happened, but we don't want to crash the program just because logging failed
                      print('XML highlighting failed: %s' % e)
          return super(PrettyXmlHandler, self).emit(record)
docs: Pretty-print and syntax highlight a log statement if all these conditions are met:
             * This is a DEBUG message
             * We're outputting to a terminal
             * The log message args is a dict containing keys starting with 'xml_' and values as bytes