Fix formatting for ReverseStack and test files

src/main/java/com/thealgorithms/datastructures/stacks/ReverseStack.java

@@ -37,19 +37,18 @@ private ReverseStack() {
      *
      * @param stack the stack to reverse; should not be null
      */
-public static void reverseStack(Stack<Integer> stack) {
-    if (stack == null) {
-        throw new IllegalArgumentException("Stack cannot be null");
-    }
-    if (stack.isEmpty()) {
-        return;
-    }
-
-    int element = stack.pop();
-    reverseStack(stack);
-    insertAtBottom(stack, element);
-}
+    public static void reverseStack(Stack<Integer> stack) {
+        if (stack == null) {
+            throw new IllegalArgumentException("Stack cannot be null");
+        }
+        if (stack.isEmpty()) {
+            return;
+        }
 
+        int element = stack.pop();
+        reverseStack(stack);
+        insertAtBottom(stack, element);
+    }
 
     /**
      * Inserts the specified element at the bottom of the stack.

src/test/java/com/thealgorithms/datastructures/stacks/ReverseStackTest.java

@@ -10,12 +10,9 @@
 class ReverseStackTest {
 
     @Test
-void testReverseNullStack() {
-    assertThrows(IllegalArgumentException.class,
-        () -> ReverseStack.reverseStack(null),
-        "Reversing a null stack should throw an IllegalArgumentException.");
-}
-
+    void testReverseNullStack() {
+        assertThrows(IllegalArgumentException.class, () -> ReverseStack.reverseStack(null), "Reversing a null stack should throw an IllegalArgumentException.");
+    }
 
     @Test
     void testReverseEmptyStack() {