Please solve the programming task below using a self-contained code snippet in a markdown code block.

Given the head of a linked list, we repeatedly delete consecutive sequences of nodes that sum to 0 until there are no such sequences.
After doing so, return the head of the final linked list.  You may return any such answer.
 
(Note that in the examples below, all sequences are serializations of ListNode objects.)
Please complete the following python code precisely:
```python
# Definition for singly-linked list.
# class ListNode:
#     def __init__(self, val=0, next=None):
#         self.val = val
#         self.next = next
class Solution:
    def removeZeroSumSublists(self, head: Optional[ListNode]) -> Optional[ListNode]:
```