parse static method
Implementation
static CSSLength? parse(String? value) {
if (value == null) return null;
var match = pattern.firstMatch(value);
if (match == null) return null;
var nStr = match.group(1);
num n;
if (isInt(nStr)) {
n = parseInt(nStr)!;
} else if (isDouble(nStr)) {
n = parseDouble(nStr)!;
} else {
return null;
}
var unit = parseCSSUnit(match.group(2), CSSUnit.px)!;
return CSSLength(n, unit);
}