Iowa State University Java Method Program

I’m working on a programming question and need an explanation and answer to help me learn.

   /**
    * Inserts one array into another at the given position. Existing elements are
    * shifted to the right. For example, if arr is [10, 20, 30, 40, 50, 60], pos is
    * 1, and toInsert is the array [101, 102, 103], then after calling this method,
    * arr contains [10, 101, 102, 103, 20, 30]. If pos plus the length of toInsert
    * exceeds the length of arr, the extra elements of toInsert are ignored. If pos
    * is out of range, the method does nothing.
    *
    * @param arr      given array to be modified
    * @param pos      starting insert position
    * @param toInsert elements to be inserted
    */
   public static void insertArray(int[] arr, int pos, int[] toInsert) {