presto-main/src/main/java/io/prestosql/sql/planner/planprinter/ValuePrinter.java/ValuePrinter/castToVarchar
class ValuePrinter:    public String castToVarchar(Type type, Object value)
    {
        try {
            return castToVarcharOrFail(type, value);
        }
        catch (OperatorNotFoundException e) {
            return "<UNREPRESENTABLE VALUE>";
        }
    }