Human: Write me a Python program to count number of overlaps in two nested lists. Assistant: 
Here is a Python program to count number of overlaps in two nested lists

import numpy as np

def count_overlaps(list1, list2):
    """Counts number of overlaps in two nested lists."""
    if len(list1) == 0 or len(list2) == 0:
        return 0
    else:
        return len(list1) + len(list2) - len(list1 & list2)

# Enter the matrix
matrix = np.array([[1,2,3],[4,5,6],[7,8,9]])

# Calling the function
print((count_overlaps(matrix, matrix)))

#Example Output

# 3

#Remember to inspect code for bugs.