protected BasicIndexScan getIndex(final LeafNodePlan plan,
final BasicIndexScan indexScan,
final Collection<Variable> sortCriterium,
final Map<Variable, Literal> minima,
final Map<Variable, Literal> maxima) {
final BasicIndexScan index1 = new MemoryIndexScan((OperatorIDTuple) null, plan.getTriplePatterns(), indexScan.getGraphConstraint(), indexScan.getRoot());
return index1;
}