JAVA - please complete method SearchForInteger()

public class SearchForInteger { /** Search a binary tree of integers for a target integer and return a list of all the addresses in the tree where the target integer is located.

An "address" is a string made up of the characters 'r', 'L' and 'R'. The root of a tree has address "r". If a node in the tree has address adr, then that node's left child has address adr+"L" and that node's right child has address adr+"R" (notice how that is a recursive definition of an address). */