Convert obj to json string representation.

        :param obj: pseudo 'self'
        :param indent: indent argument to dumps
        :param kwargs: other arguments for dumps
        :return: JSON formatted string

def as_json(obj: JsonObj, indent: Optional[str]='   ', **kwargs) -> str:
    """ Convert obj to json string representation.

        :param obj: pseudo 'self'
        :param indent: indent argument to dumps
        :param kwargs: other arguments for dumps
        :return: JSON formatted string
       """
    return obj._as_json_dumps(indent, **kwargs)