insertAll method
override
    Throws an UnsupportedError; operations that change the length of the list are disallowed.
Implementation
@override
void insertAll(int index, Iterable<E> iterable) => _throw();Throws an UnsupportedError; operations that change the length of the list are disallowed.
@override
void insertAll(int index, Iterable<E> iterable) => _throw();