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

Winston was given the above mysterious function func. He has an integer array arr and an integer target and he wants to find the values l and r that make the value |func(arr, l, r) - target| minimum possible.
Return the minimum possible value of |func(arr, l, r) - target|.
Notice that func should be called with the values l and r where 0 <= l, r < arr.length.
 
Please complete the following python code precisely:
```python
class Solution:
    def closestToTarget(self, arr: List[int], target: int) -> int:
```