public int readInt(DataInput in) throws IOException {
        return strategy.readInt(in);
    }
Reads an array of long values. This method will return {@code null} if
the array written to the stream was {@code null}.

@param in the input stream.
@return an array of long values.
@throws IOException if an error occurs.
xmppserver/src/main/java/org/jivesoftware/util/cache/ExternalizableUtil.java