To start the implementation of an abstract datatype for Red Black-tree. The type of it should be 'a rbTree. Every node should contain a tuple of type int * 'a, whose first element in the tuple is a key, which is an integer, and the second element in the tuple is a satellite data corresponding the key.
Implement the function insert: (int * 'a) -> 'a rbTree -> 'a rbTree, which takes an element of type int * 'a as the first argument, an Red Black-tree with n elements as the second argument, and returns, a new Red Black-tree that is the given tree into which the input element was inserted. The time complexity of this function should be O(lg n)
Implement the function inOrder: 'a rbTree -> (int * 'a) list, which takes a Red Black-tree as argument and returns the in-order walk, represented as a list, of the Red Black-tree.