Double Down

Complete the function double_down so that it receives a number num and
an integer times_doubled and returns num doubled times_doubled amount of times.
Use a while loop to do this (and for everyone's sake, no infinite loops!).

Examples:

>>>  double_down(3, 3)
24

>>>  double_down(2, 0)
2

>>>  double_down(4, 1)
8

Test Cases

test double zero times - Run Test 

def test_double_zero_times():
    assert double_down(4, 0) == 4

test double three times - Run Test 

def test_double_three_times():
    assert double_down(3, 3) == 24

test double one time - Run Test 

def test_double_one_time():
    assert double_down(2, 1) == 4

Solution 1 

def double_down(num, times_doubled):
    count = 0
    while count < times_doubled:
        num *= 2
        count += 1
    return num
def double_down(num, times_doubled): pass
Python 3.6