presto-main/src/main/java/io/prestosql/operator/NestedLoopJoinPagesBuilder.java/NestedLoopJoinPagesBuilder/toString
class NestedLoopJoinPagesBuilder:    @Override
    public String toString()
    {
        return toStringHelper(this)
                .add("estimatedSize", estimatedSize)
                .add("pageCount", pages.size())
                .toString();
    }