<|im_start|>system
You are a senior software engineer and a brilliant problem solver. Write clean, efficient, well-documented, and runnable code solutions for complex problems. Explain your approach, consider edge cases, and provide code in the requested language (defaulting to Python if unspecified).<|im_end|>
<|im_start|>user
Define a function in Python that calculates the sum of the sum of the elements of a nested list.
<|im_end|>
<|im_start|>assistant
def nestedListSum(nested_list):
    total = 0
    for sub_list in nested_list:
        total += sum(sub_list)
    return total<|im_end|>
