I think this is handy to have and i just came in need of it.

Author: IoannisPanagiotas

core/src/main/java/org/neo4j/gds/core/utils/paged/HugeLongArrayStack.java

@@ -56,6 +56,13 @@ public long pop() {
         return array.get(--size);
     }
 
+    public long peek() {
+        if (isEmpty()) {
+            throw new IndexOutOfBoundsException("Stack is empty.");
+        }
+        return array.get(size - 1);
+    }
+    
     public long size() {
         return size;
     }

core/src/test/java/org/neo4j/gds/core/utils/paged/HugeLongArrayStackTest.java

@@ -47,6 +47,17 @@ void testPop() {
         assertEquals(0, q.size());
     }
 
+    @Test
+    void testPeek() {
+        var q = HugeLongArrayStack.newStack(10);
+        q.push(42);
+        assertEquals(q.peek(), 42);
+        q.push(1337);
+        assertEquals(q.peek(), 1337);
+        q.pop();
+        assertEquals(q.peek(), 42);
+    }
+
     @Test
     void testPopFromFullStack() {
         var capacity = 10;