code: public static int delete(String query, Object... params) {
          return ModelDelegate.delete(modelClass(), query, params);
      }
docs: Deletes some records from associated table. This method does not follow any associations.
  If this model has one to many associations, you might end up with either orphan records in child
  tables, or run into integrity constraint violations. However, this method if very efficient as it deletes all records
  in one shot, without pre-loading them.
  This method also has a side-effect: it will not mark loaded instances corresponding to deleted records as "frozen".
  This means that such an instance would allow calling save() and saveIt() methods resulting DB errors, as you
  would be attempting to update phantom records.
  
  
  @param query narrows which records to delete. Example: <pre>"last_name like '%sen%'"</pre>.
  @param params   (optional) - list of parameters if a query is parametrized.
  @return number of deleted records.