@staticmethod
def _create_html_message(plain_message_string):
    """
        Internal method to convert plain-text message string to HTML.

        :param plain_message_string: The message string to converted to HTML.

        :return: The HTML-based message string.
        :rtype: str
        """
    return '<html><head></head><body><p>' + str(plain_message_string
        ) + '</p></body></html>'
