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
dynamic operator [](int index) {
var value = _dartList[index];
if (value is Map) return YamlMapWrapper._(value, span);
if (value is List) return YamlListWrapper._(value, span);
return value;
}