/**
* Sets the value of a specific piece of statistics. The method assumes that the caller has
* acquired the write lock of {@link #lock} and, thus, allows the optimization of batch updates to
* multiple pieces of statistics.
*
* @param stat the piece of statistics to set
* @param value the value of the piece of statistics to set
*/
protected void unlockedSetStat(String stat, Object value) {
if (value == null) stats.remove(stat);
else stats.put(stat, value);
}
