Get a specific canned value

        :type value: str
        :param value: Canned value to show

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

def show_value(self, value):
        """
        Get a specific canned value

        :type value: str
        :param value: Canned value to show

        :rtype: dict
        :return: A dictionnary containing canned value description
        """
        values = self.get_values()
        values = [x for x in values if x['label'] == value]
        if len(values) == 0:
            raise Exception("Unknown value")
        else:
            return values[0]