operator * method
Implementation
@override
XPathNumeric operator *(XPathNumeric other) => switch (other) {
final XPathInteger i => this * i.toDecimal(),
final XPathDecimal d => XPathDecimal(
unscaledValue * d.unscaledValue,
scale + d.scale,
),
final XPathDouble d => XPathDouble(toDouble() * d.value),
};