question: private void buildSubgraphs ( List subgraphList , PolygonBuilder polyBuilder ) { List processedGraphs = new ArrayList ( ) ; for ( Iterator i = subgraphList . iterator ( ) ; i . hasNext ( ) ; ) { BufferSubgraph subgraph = ( BufferSubgraph ) i . next ( ) ; Coordinate p = subgraph . getRightmostCoordinate ( ) ; SubgraphDepthLocater locater = new SubgraphDepthLocater ( processedGraphs ) ; int outsideDepth = locater . getDepth ( p ) ; subgraph . computeDepth ( outsideDepth ) ; subgraph . findResultEdges ( ) ; processedGraphs . add ( subgraph ) ; polyBuilder . add ( subgraph . getDirectedEdges ( ) , subgraph . getNodes ( ) ) ; } }
target:  Completes the building of the input subgraphs by depth-labelling them, and adds them to the PolygonBuilder. The subgraph list must be sorted in rightmost-coordinate order.