@Override
    public <K, V> Map<K, V> asMap(Class<K> keyClass, Class<V> valueClass) {
        if (keyClass == null || valueClass == null) {
            throw new IllegalArgumentException("Non-null key and value classes are required");
        }
        Map<K, V> map = new LinkedHashMap<>();
        int index = 1;
        for (Object o : getValue()) {
            map.put(keyClass.cast(index++), valueClass.cast(o));
        }
        // why not use Collections.unmodifiableMap(map) here?
        return map;
    }
Update value of the given object or create a new instance if {@code ref} is
null.

@param <T>   type of element
@param ref   object to update, could be null
@param value value
@return same object as {@code ref} or a new instance if it's null
clickhouse-data/src/main/java/com/clickhouse/data/value/ClickHouseArrayValue.java