#fixed code
                                public static <T extends Number> double mean(final Iterable<T> iterable) {
        T result = null;
        int count = 0;
        for (final T item : iterable) {
            result = add(result, item);
            count += 1;
        }
        if (result == null) {
            return 0d;
        }
        return result.doubleValue() / count;
    }
#vulnerable code 
                                public static <T extends Number> double mean(final Iterable<T> iterable) {
        T result = null;
        int count = 0;
        for (final T item : iterable) {
            result = add(result, item);
            count += 1;
        }
        return result.doubleValue() / count;
    } 
                            #location 8 
                            #vulnerability type NULL_DEREFERENCE