presto-parser/src/main/java/io/prestosql/sql/tree/DefaultTraversalVisitor.java/DefaultTraversalVisitor/visitSearchedCaseExpression
class DefaultTraversalVisitor:    @Override
    protected R visitSearchedCaseExpression(SearchedCaseExpression node, C context)
    {
        for (WhenClause clause : node.getWhenClauses()) {
            process(clause, context);
        }
        node.getDefaultValue()
                .ifPresent(value -> process(value, context));

        return null;
    }