@classmethod
def format_source(cls, message_type, host, path):
    """Format the source field of the log record.

        Args:
            message_type (str): Type of the log record message.
            host (str): Hostname or the fully qualified domain where the logging call was made.
            path (str): The full pathname of the source file where the logging call was made.

        Returns:
            string: URI of the file where the logging call was made.
        """
    return f'{message_type}://{host}/{path}'
