range static method
"ranging 20 to 95" — handy when listing every point would be noise.
Implementation
static String range(List<double> values) {
if (values.isEmpty) return '';
final lo = values.reduce((a, b) => a < b ? a : b);
final hi = values.reduce((a, b) => a > b ? a : b);
return 'ranging ${number(lo)} to ${number(hi)}';
}