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

Given an integer array nums, return true if nums is consecutive, otherwise return false.
An array is consecutive if it contains every number in the range [x, x + n - 1] (inclusive), where x is the minimum number in the array and n is the length of the array.
 
Please complete the following python code precisely:
```python
class Solution:
    def isConsecutive(self, nums: List[int]) -> bool:
```