src/main/java/org/jivesoftware/smack/util/collections/AbstractHashedMap.java
protected void checkCapacity() {
        if (size >= threshold) {
            int newCapacity = data.length * 2;
            if (newCapacity <= MAXIMUM_CAPACITY) {
                ensureCapacity(newCapacity);
            }
        }
    }
protected void checkCapacity() {
        if (size >= threshold) {
            int newCapacity = data.length * 2;
            if (newCapacity <= MAXIMUM_CAPACITY) {
                ensureCapacity(newCapacity);
            }
        }
    }
Checks the capacity of the map and enlarges it if necessary.
<p/>
This implementation uses the threshold to check if the map needs
enlarging