/**
* Extract results from a query result according to the given specification.
- * If colums are NULL, the destination is not modified, and #GNUNET_NO
- * is returned.
*
* @param result result to process
* @param[in,out] rs result specification to extract for
* @param row row from the result to extract
* @return
* #GNUNET_YES if all results could be extracted
- * #GNUNET_NO if at least one result was NULL
* #GNUNET_SYSERR if a result was invalid (non-existing field)
*/
int