presto-parser/src/main/java/io/prestosql/sql/tree/SimpleCaseExpression.java/SimpleCaseExpression/getChildren
class SimpleCaseExpression:    @Override
    public List<Node> getChildren()
    {
        ImmutableList.Builder<Node> nodes = ImmutableList.builder();
        nodes.add(operand);
        nodes.addAll(whenClauses);
        defaultValue.ifPresent(nodes::add);
        return nodes.build();
    }