boolean is19 = !lexer.isOneEight();
if (contents == null) {
ByteList newValue = ByteList.create("");
regexpFragmentCheck(end, newValue);
return new RegexpNode(position, newValue, options.withoutOnce());
} else if (contents instanceof StrNode) {
ByteList meat = (ByteList) ((StrNode) contents).getValue().clone();
regexpFragmentCheck(end, meat);
checkRegexpSyntax(meat, options.withoutOnce());
return new RegexpNode(contents.getPosition(), meat, options.withoutOnce());
} else if (contents instanceof DStrNode) {
DStrNode dStrNode = (DStrNode) contents;
for (Node fragment: dStrNode.childNodes()) {
if (fragment instanceof StrNode) {