@Override
    public Set<K> keySet() {
        return getCollection().getKeySet();
    }
Return a {@link Set} for iterating over and interacting with all keys
in the array map.
<p/>
<p><b>Note:</b> this is a fairly inefficient way to access the array contents, it
requires generating a number of temporary objects.</p>
replugin-host-library/replugin-host-lib/src/main/java/com/qihoo360/replugin/utils/basic/ArrayMap.java