private static OrdinalSet<InstanceKey> findReachableInstances( final PointerAnalysis<InstanceKey> pts, final PointerKey pkStart) { final HeapGraph hg = pts.getHeapGraph(); if (!hg.containsNode(pkStart)) { return OrdinalSet.empty(); } final OrdinalSetMapping<InstanceKey> mapping = pts.getInstanceKeyMapping(); final BitVectorIntSet resultSet = new BitVectorIntSet(); final NumberedDFSDiscoverTimeIterator<Object> dfsDiscover = new NumberedDFSDiscoverTimeIterator<Object>(hg, pkStart); while (dfsDiscover.hasNext()) { Object obj = dfsDiscover.next(); if (obj instanceof InstanceKey) { InstanceKey ik = (InstanceKey) obj; final int ikNum = mapping.getMappedIndex(ik); resultSet.add(ikNum); } } final OrdinalSet<InstanceKey> reachable = new OrdinalSet<InstanceKey>(resultSet, mapping); return reachable; }