operator [] method Null safety

dynamic operator [](
  1. int index
)

[0] retrieves first item [1] retrieves 2nd, negative numbers retrieve [0] if even or [1] if odd

Implementation

operator [](int index) {
  if (index == 0) {
    return item1;
  } else if (index == 1) {
    return item2;
  } else if (index < 0) {
    return this[(index % 2)];
  }
  throw RangeError('$index is out of range (only 1 and 2)');
}