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

        checkKey(key);

        return lookupValid(key, KEY, getCurrentThreadId()) != null;
    }
@Override
    public boolean containsKey(final Object key)
            throws ClassCastException, NullPointerException {

        checkKey(key);

        return lookupValid(key, KEY, getCurrentThreadId()) != null;
    }
Returns true if this map contains a mapping for the specified
key.

@param key key whose presence in this map is to be tested.

@return true if this map contains a mapping for the specified
key.

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