python how to test random choice

How would you test a function which could lead to a random choice. For instance:

def getMaxIndices(lst):
    '''
    :lst: list of int

    Return indices of max value. If max value appears more than once,
    we chose one of its indices randomly. 
    '''
    index_lst = [(i, j) for i in enumerate(lst)]
    shuffle(index_lst)
    index_lst.sort(key=lambda x: x[1])
    max_index = index_lst.pop()[0]
    return max_index

I can't find a satisfying way to test it.

How would you do ?