presto-main/src/main/java/io/prestosql/operator/index/PagesIndexBuilderOperator.java/PagesIndexBuilderOperator/PagesIndexBuilderOperator
class PagesIndexBuilderOperator:    public PagesIndexBuilderOperator(OperatorContext operatorContext, IndexSnapshotBuilder indexSnapshotBuilder)
    {
        this.operatorContext = requireNonNull(operatorContext, "operatorContext is null");
        this.indexSnapshotBuilder = requireNonNull(indexSnapshotBuilder, "indexSnapshotBuilder is null");
    }