size_t *ret_buffer_free);
int format_kairosdb_value_list(char *buffer, size_t *ret_buffer_fill,
size_t *ret_buffer_free, const data_set_t *ds,
size_t *ret_buffer_free);
int format_kairosdb_value_list(char *buffer, size_t *ret_buffer_fill,
size_t *ret_buffer_free, const data_set_t *ds,