validateSingle method
Implementation
bool validateSingle(dynamic value) {
if (value == null) return true;
var n = value as num;
if (min != null) {
if (minExclusive) {
if (n <= min!) return false;
} else {
if (n < min!) return false;
}
}
if (max != null) {
if (maxExclusive) {
if (n >= max!) return false;
} else {
if (n > max!) return false;
}
}
return true;
}