public override String ToString()
{
String s = string.Empty;
String delim = string.Empty;
try {
foreach (var interval in _intervals.Cast<int[]>())
{
s += (delim + ToString(interval[0]));
if (interval[0] < interval[1]) {
s += ("-" + ToString(interval[1]));
}
delim = ",";
}
} catch (IndexOutOfRangeException) {
}
if (Size() == 1) {
return s;
}
return "{" + s + "}";
}