LeetCode Hard: Merge k sorted Lists

I just solved LeetCode hard problem #23: Merge k sorted Lists, which is asked in interviews for a lot of companies, including Facebook, Uber, Google and you name it! It can look intimidating but...

Hint: It's too easy if you can think of the right Data Structure for solving the problem.

Here's my O(lg n) solution where n is the cardinality of all the elements combined in all lists:

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode() {}
 *     ListNode(int val) { this.val = val; }
 *     ListNode(int val, ListNode next) { this.val = val; this.next = next; }
 * }
 */
class Solution {
    public ListNode mergeKLists(ListNode[] lists) {
        ListNode dummy = new ListNode(-1);
        
        PriorityQueue<Integer> minHeap = new PriorityQueue<>();
        
        for(ListNode list : lists) {
            while (list != null) {
                minHeap.add(list.val);
                list = list.next;
            }
        }
        
        ListNode head = dummy;
        while (!minHeap.isEmpty()) {
            head.next = new ListNode(minHeap.remove());
            head = head.next;
        }
        
        return dummy.next;
    }
}

Feel free to share your thoughts below!