Попробуйте это:
public static int? ParseNullableInt(this string value)
{
int intValue;
if (int.TryParse(value, out intValue))
return intValue;
return null;
}
As long as the callbacks defined in the behavior don't conflict with a callback of another behavior (say you defined your own behavior, for example) then there's nothing wrong with doing this other than potentially more confusing code. Obviously you can curb that with some well placed comments and laying the code out sensibly in the file.