/**
* Remove all keys in the array map that do <b>not</b> exist in the given collection.
*
* @param collection The collection whose contents are to be used to determine which keys to keep.
* @return Returns true if any keys were removed from the array map, else false.
*/
public boolean retainAll(Collection<?> collection) {
return MapCollections.retainAllHelper(this, collection);
}
/**
* Determine if the array map contains all of the keys in the given collection.
*
* @param collection The collection whose contents are to be checked against.
* @return Returns true if this array map contains a key for every entry in <var>collection</var>,
* else returns false.
*/
public boolean containsAll(Collection<?> collection) {
return MapCollections.containsAllHelper(this, collection);
}