operator [] method
The object at the given index in the list.
The index must be a valid index of this list,
which means that index must be non-negative and
less than length.
Implementation
@override
T operator [](int index) {
RangeError.checkValidIndex(index, this);
return _cache[index] ??= _readItem(RecordReader.fromPayloadOffset(_ptr, _offsets[index]));
}