### Attention Mechanism
Implement a basic attention mechanism for a transformer model.
Example:
* Input: query = np.array([1, 2, 3]), key = np.array([4, 5, 6]), value = np.array([7, 8, 9])
* Output: np.array([7.0, 8.0, 9.0])
Constraints:
* Use NumPy for calculations.
Test Cases
Test Case 1
Input:
np.array([1, 2, 3]), np.array([4, 5, 6]), np.array([7, 8, 9])Expected:
np.array([7.0, 8.0, 9.0])Test Case 2
Input:
np.array([10, 20, 30]), np.array([40, 50, 60]), np.array([70, 80, 90])Expected:
np.array([70.0, 80.0, 90.0])+ 3 hidden test cases