docs: protected IntHashSet findBorderEdgeIds(SpatialRuleLookup ruleLookup) {
          AllEdgesIterator allEdgesIterator = graph.getAllEdges();
          NodeAccess nodeAccess = graph.getNodeAccess();
          IntHashSet inaccessible = new IntHashSet();
          while (allEdgesIterator.next()) {
              int adjNode = allEdgesIterator.getAdjNode();
              SpatialRule ruleAdj = ruleLookup.lookupRule(nodeAccess.getLatitude(adjNode), nodeAccess.getLongitude(adjNode));
  
              int baseNode = allEdgesIterator.getBaseNode();
              SpatialRule ruleBase = ruleLookup.lookupRule(nodeAccess.getLatitude(baseNode), nodeAccess.getLongitude(baseNode));
              if (ruleAdj != ruleBase) {
                  inaccessible.add(allEdgesIterator.getEdge());
              }
          }
          return inaccessible;
      }