use in java please be quick

Expected Functionality Complete the missing parts of the MergeForIntegers class, shuch that it sorts a given integer array using Merge Sort which uses Insertion Sort when the length of the sub array is less than 4 . Hints: 1. This code is specialized for int type, therefore you should use int instead of Comparable. 2. It is already mentioned above but once again: when the length of the subarray is less than 4 your implementation it should call Insertion Sort instead of Merge sort. 3. This time we use Input/Output test instead of Unit Test therefore in case your code passes the test you will see something like following