Cheqq has already solved number 6 here. so only answer number 7. only the number 7 answer is what I need. the question belongs to analysis and algorithm.

I mean answer the number 7 question. based on your knowledge about number 6. you can still answer both. waiting for your answers.

6. Define a treeNode class for tree nodes that each consists of following 4 fields: parent leftChild rightChild data 7. Following the above node definition, define and implement a binary tree class with necessary access methods for the 4-field treeNodes, for example, setXXX, getXXX, isEmpty, etc