### Question:
IntList { public static void dSquareList(IntList L) { while (L != null) { L.first = L.first * L.first; L = L.rest; } } IntList(int first0, IntList rest0);  IntList(); static void dSquareList(IntList L); static IntList squareListIterative(IntList L); static IntList squareListRecursive(IntList L); static IntList dcatenate(IntList A, IntList B); static IntList catenate(IntList A, IntList B); @Override int hashCode(); static IntList of(Integer... args); boolean equals(Object x); @Override /** Outputs the IntList as a String. You are not expected to read * or understand this method. */ String toString(); static IntList reverse(IntList A); IntList dereverse(); public int first; public IntList rest; }### Answer:
@Test public void testdSquareList() { IntList L = IntList.of(1, 2, 3); IntList.dSquareList(L); assertEquals(IntList.of(1, 4, 9), L); }