Add a canned comment

        :type comment: str
        :param comment: New canned comment

        :type metadata: str
        :param metadata: Optional metadata

        :rtype: dict
        :return: A dictionnary containing canned comment description

def add_comment(self, comment, metadata=""):
        """
        Add a canned comment

        :type comment: str
        :param comment: New canned comment

        :type metadata: str
        :param metadata: Optional metadata

        :rtype: dict
        :return: A dictionnary containing canned comment description
        """
        data = {
            'comment': comment,
            'metadata': metadata
        }

        return self.post('createComment', data)