Write a function to extract every first or specified element from a given two-dimensional list.
def specified_element(nums, N):
    result = [i[N] for i in nums]
    return result
    
<s>[INST]<<SYS>>Given a task and its code, generate test cases for the code.<</SYS>>Write a function to extract every first or specified element from a given two-dimensional list.
def specified_element(nums, N):
    result = [i[N] for i in nums]
    return result
    [/INST]assert specified_element([[1, 2, 3, 2], [4, 5, 6, 2], [7, 1, 9, 5]],0)==[1, 4, 7]
assert specified_element([[1, 2, 3, 2], [4, 5, 6, 2], [7, 1, 9, 5]],2)==[3, 6, 9]
assert specified_element([[1, 2, 3, 2], [4, 5, 6, 2], [7, 1, 9, 5]],1)==[2,5,1]</s>