visitDelimited method
Implementation
@override
String visitDelimited(DelimitedNode node) {
final content = node.content.map((it) => visit(it)).join("");
final left = (node.left.isNotEmpty && node.left != ".")
? '<mo stretchy="true">${_escapeXml(node.left)}</mo>'
: "";
final right = (node.right.isNotEmpty && node.right != ".")
? '<mo stretchy="true">${_escapeXml(node.right)}</mo>'
: "";
return _mrow("$left$content$right");
}