Remove comments automatically inserted by the ide.
Implement the contains() method in terms of get() and move it into the base class.  Does not have to be overiden by the base classes -- they just implement get.
Implement the contains() method in terms of get() and move it into the base class.  Does not have to be overiden by the base classes -- they just implement get (this is for the red black tree -- already done for the brother tree).
Make some methods final.
Delete the contains() method from some of the auxiliary Tree subclasses.  It no longer needs to be overwritten.
Implement getWithDefault() in terms of get in the base class and remove it from the subclasses.
Implement getWithDefault() in terms of get in the base class and remove it from the subclasses (for the red-black tree).