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

You have an undirected, connected graph of n nodes labeled from 0 to n - 1. You are given an array graph where graph[i] is a list of all the nodes connected with node i by an edge.
Return the length of the shortest path that visits every node. You may start and stop at any node, you may revisit nodes multiple times, and you may reuse edges.
 
Please complete the following python code precisely:
```python
class Solution:
    def shortestPathLength(self, graph: List[List[int]]) -> int:
```