public void writeLongIntMap(DataOutput out, Map<Long, Integer> map) throws IOException {
        strategy.writeLongIntMap(out, map);
    }
Writes a Map of Long key and Integer value pairs. This method handles
the case when the Map is {@code null}.

@param out the output stream.
@param map the Map of Long key/Integer value pairs.
@throws IOException if an error occurs.
xmppserver/src/main/java/org/jivesoftware/util/cache/ExternalizableUtil.java