presto-main/src/main/java/io/prestosql/operator/scalar/ArraySubscriptOperator.java/ArraySubscriptOperator/objectSubscript
class ArraySubscriptOperator:    @UsedByGeneratedCode
    public static Object objectSubscript(Type elementType, Block array, long index)
    {
        checkIndex(array, index);
        int position = toIntExact(index - 1);
        if (array.isNull(position)) {
            return null;
        }

        return elementType.getObject(array, position);
    }