Write a python function to find the largest negative number from the given list.
def largest_neg(list1): 
    max = list1[0] 
    for x in list1: 
        if x < max : 
             max = x  
    return max
<s>[INST]<<SYS>>Given a task and its code, generate test cases for the code.<</SYS>>Write a python function to find the largest negative number from the given list.
def largest_neg(list1): 
    max = list1[0] 
    for x in list1: 
        if x < max : 
             max = x  
    return max[/INST]assert largest_neg([1,2,3,-4,-6]) == -6
assert largest_neg([1,2,3,-8,-9]) == -9
assert largest_neg([1,2,3,4,-1]) == -1</s>