code: @Override
  	public void setDBRefs(List<DBRef> dbrefs) {
  		if ( dbrefs == null)
  			throw new IllegalArgumentException("trying to set dbrefs to null!");
  
  		for( DBRef ref : dbrefs){
  			ref.setParent(this);
  		}
  		this.dbrefs = dbrefs;
  	}
docs: {@inheritDoc}