question: private void findCollapsesFromInsertedNodes ( List collapsedVertexIndexes ) { int [ ] collapsedVertexIndex = new int [ 1 ] ; Iterator it = iterator ( ) ; SegmentNode eiPrev = ( SegmentNode ) it . next ( ) ; while ( it . hasNext ( ) ) { SegmentNode ei = ( SegmentNode ) it . next ( ) ; boolean isCollapsed = findCollapseIndex ( eiPrev , ei , collapsedVertexIndex ) ; if ( isCollapsed ) collapsedVertexIndexes . add ( new Integer ( collapsedVertexIndex [ 0 ] ) ) ; eiPrev = ei ; } }
target:  Adds nodes for any collapsed edge pairs caused by inserted nodes Collapsed edge pairs occur when the same coordinate is inserted as a node both before and after an existing edge vertex. To provide the correct fully noded semantics, the vertex must be added as a node as well.