code: public <T extends Object> void deleteAll(Class<T> clazz) {
          Preconditions.checkNotNull(clazz, "Tryed to delete list of mapped morphia objects, but given class is null");
  
          this.datastore.delete(this.datastore.createQuery(clazz));
      }
docs: Deletes all mapped Morphia objects of a given class
  
  @param <T> JavaDoc requires this - please ignore
  @param clazz The mapped Morphia class