presto-main/src/main/java/io/prestosql/sql/planner/plan/SampleNode.java/SampleNode/replaceChildren
class SampleNode:    @Override
    public PlanNode replaceChildren(List<PlanNode> newChildren)
    {
        return new SampleNode(getId(), Iterables.getOnlyElement(newChildren), sampleRatio, sampleType);
    }