- E: for( final PhylogenyNodeIterator it = phy.iteratorExternalForward(); it.hasNext(); ) {
- final PhylogenyNode ext_node = it.next();
- PhylogenyNode n = ext_node;
- while ( !n.isRoot() ) {
- if ( n.isCollapse() ) {
- _collapsed_external_nodeid_set.add( ext_node.getId() );
- continue E;
+ if ( phy != null ) {
+ E: for( final PhylogenyNodeIterator it = phy.iteratorExternalForward(); it.hasNext(); ) {
+ final PhylogenyNode ext_node = it.next();
+ PhylogenyNode n = ext_node;
+ while ( !n.isRoot() ) {
+ if ( n.isCollapse() ) {
+ _collapsed_external_nodeid_set.add( ext_node.getId() );
+ ext_node.setCollapse( true );
+ continue E;
+ }
+ n = n.getParent();