src/main/java/com/workplacesystems/utilsj/collections/TransactionalBidiTreeMap.java
@Override
    public V get(final Object key)
            throws ClassCastException, NullPointerException {

        checkKey(key);

        return (V)doGet(key, KEY);
    }
@Override
    public V get(final Object key)
            throws ClassCastException, NullPointerException {

        checkKey(key);

        return (V)doGet(key, KEY);
    }
Returns the value to which this map maps the specified
key. Returns null if the map contains no mapping for this key.

@param key key whose associated value is to be returned.

@return the value to which this map maps the specified key, or
null if the map contains no mapping for this key.

@throws ClassCastException if the key is of an inappropriate
type for this map.
@throws NullPointerException if the key is null