// d
// / \
// b f
// \ \
// c g
SimpleNode c = new SimpleNode('c', null, null);
SimpleNode b = new SimpleNode('b', null, c);
SimpleNode g = new SimpleNode('g', null, null);
SimpleNode f = new SimpleNode('f', null, g);
SimpleNode d = new SimpleNode('d', b, f);
BstMutationResult<Character, SimpleNode> extractMin =
BstOperations.extractMin(d, nodeFactory, balancePolicy);
assertEquals('b', extractMin.getTargetKey().charValue());
assertEquals(d, extractMin.getOriginalRoot());