question: protected void computePoints ( DirectedEdge start ) { startDe = start ; DirectedEdge de = start ; boolean isFirstEdge = true ; do { if ( de == null ) throw new TopologyException ( "Found null DirectedEdge" ) ; if ( de . getEdgeRing ( ) == this ) throw new TopologyException ( "Directed Edge visited twice during ring-building at " + de . getCoordinate ( ) ) ; edges . add ( de ) ; Label label = de . getLabel ( ) ; Assert . isTrue ( label . isArea ( ) ) ; mergeLabel ( label ) ; addPoints ( de . getEdge ( ) , de . isForward ( ) , isFirstEdge ) ; isFirstEdge = false ; setEdgeRing ( de , this ) ; de = getNext ( de ) ; } while ( de != startDe ) ; }
target:  Collect all the points from the DirectedEdges of this ring into a contiguous list