public boolean addChild(BaseVertex vertex) {
        if ( vertex != null && vertices.add( vertex ) ) {
            firePropertyChange( PROP_CHILD_ADDED,
                                null,
                                vertex );
            return true;
        }
        return false;
    }
public boolean addChild(BaseVertex vertex) {
        if ( vertex != null && vertices.add( vertex ) ) {
            firePropertyChange( PROP_CHILD_ADDED,
                                null,
                                vertex );
            return true;
        }
        return false;
    }
public boolean addChild ( BaseVertex vertex ) { if ( vertex != null && vertices . add ( vertex ) ) { firePropertyChange ( PROP_CHILD_ADDED , null , vertex ) ; return true ; } return false ; }
Add new BaseVertex to the graph

@param vertex

@return true, if vertex was added, false otherwise
Add new BaseVertex to the graph