Goldman Sachs

We currently don't have overloads of `containsKey` and `get` but could add them. We have a similar overload of the `remove` method [MutableMapIterable.removeKey(K k): V](http://www.goldmansachs.com/gs-collections/javadoc/6.0.0/com/gs/collections/api/map/MutableMapIterable.html#removeKey-K-). We would probably use the...