public override string ToString()
{
var exp = new StringBuilder();
exp.Append(FromInclusive ? "[" : "{");
exp.Append(FromValue == null ? "*" : FromValue.Value.ToString());
exp.Append(" TO ");
exp.Append(ToValue == null ? "*" : ToValue.Value.ToString());
exp.Append(ToInclusive ? "]" : "}");
return exp.ToString();
}
