class IgniteDhtPartitionCountersMap2 implements Serializable {
    /** */
    private static final long serialVersionUID = 0L;

    /** */
    private Map<Integer, CachePartitionFullCountersMap> map;

    /**
     * @return {@code True} if map is empty.
     */
    public synchronized boolean empty() {
        return map == null || map.isEmpty();
    }

    /**
     * @param cacheId Cache ID.
     * @param cntrMap Counters map.
     */
    public synchronized void putIfAbsent(int cacheId, CachePartitionFullCountersMap cntrMap) {
        if (map == null)
            map = new HashMap<>();

        if (!map.containsKey(cacheId))
            map.put(cacheId, cntrMap);
    }

    /**
     * @param cacheId Cache ID.
     * @return Counters map.
     */
    public synchronized CachePartitionFullCountersMap get(int cacheId) {<FILL_FUNCTION_BODY>}
}

        if (map == null)
            return null;

        CachePartitionFullCountersMap cntrMap = map.get(cacheId);

        if (cntrMap == null)
            return null;

        return cntrMap;
    
<no_super_class>