public void execute ( T event ) throws Exception {
        if ( event == null )
            throw new IllegalArgumentException ( "The event received is null" ) ;

        String [] names = nameMask.get ( event.getType () );

        /**
         * If names is null it means that the handler should react to all the events of the specified type
         */
        if ( names == null )
            handle ( event );
        else //else it will react only to those events of that type which have a specific name
            for ( String name : names )
                if ( name != null && name.equals ( event.getName () ) )
                    handle ( event );
    }