// this index. It is equivalent to c1=x and c2 btw min to max.
// Default access for testability
FilterNode evalFilterForIndexSelection(Filter filter, List<IndexSpecification> indices) {
if (filter instanceof FilterList) {
FilterList fList = (FilterList) filter;
GroupingCondition condition =
(fList.getOperator() == Operator.MUST_PASS_ALL) ? GroupingCondition.AND
: GroupingCondition.OR;
NonLeafFilterNode nonLeafFilterNode = new NonLeafFilterNode(condition);
List<Filter> filters = fList.getFilters();
for (Filter fltr : filters) {