Question: 
Write a function to find the circumference of a circle.


Model's Code:
def circle_circumference(radius):
    import math
    return 2 * math.pi * radius



Sample Correct Code:
def circle_circumference(r):
  perimeter=2*3.1415*r
  return perimeter


Asserts:
assert circle_circumference(10)==62.830000000000005
assert circle_circumference(5)==31.415000000000003
assert circle_circumference(4)==25.132


Tests:
Test 1 of 3: FAIL: AssertionError()

Test 139 of 974: 101/139 (72.66187050359713%): failed