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

A good meal is a meal that contains exactly two different food items with a sum of deliciousness equal to a power of two.
You can pick any two different foods to make a good meal.
Given an array of integers deliciousness where deliciousness[i] is the deliciousness of the i​​​​​​th​​​​​​​​ item of food, return the number of different good meals you can make from this list modulo 109 + 7.
Note that items with different indices are considered different even if they have the same deliciousness value.
 
Please complete the following python code precisely:
```python
class Solution:
    def countPairs(self, deliciousness: List[int]) -> int:
```