def validate_message_text(self, message_string):
if isinstance(message_string, str):<EOL><INDENT>for regex in self.regexes:<EOL><INDENT>if regex.match(message_string) is not None:<EOL><INDENT>raise ApiKeyIncludedException()<EOL><DEDENT><DEDENT><DEDENT>
With a message string, check to see if it contains a SendGrid API Key
            If a key is found, throw an exception

           :param message_string: message that will be sent
           :type message_string: string
           :raises ApiKeyIncludedException: If message_string matches a regex
                                            string