add method
Adds value
to the end of this list,
extending the length by one.
The list must be growable.
final numbers = <int>[1, 2, 3];
numbers.add(4);
print(numbers); // [1, 2, 3, 4]
Implementation
@override
void add(E? element) {
if (_length == _list.length) {
_list.length *= 2;
}
_list[_length++] = element;
}