Please help with this method for BST

/**

* Finds and retrieves the k-largest elements from the BST in sorted order,

* least to greatest.

*

* In most cases, this method will not need to traverse the entire tree to

* function properly, so you should only traverse the branches of the tree

* necessary to get the data and only do so once. Failure to do so will

* result in the efficiency penalty.

*

* EXAMPLE: Given the BST below composed of Integers:

*

* 50

* / \

* 25 75

* / \

* 12 37

* / \ \

* 10 15 40

* /

* 13

*

* kLargest(5) should return the list [25, 37, 40, 50, 75].

* kLargest(3) should return the list [40, 50, 75].

*

* Should have a running time of O(log(n) + k) for a balanced tree and a

* worst case of O(n + k).

*

* @throws java.lang.IllegalArgumentException if k > n, the number of data

* in the BST

* @param k the number of largest elements to return

* @return sorted list consisting of the k largest elements

*/

public List kLargest(int k) {

}