input: Write a function to take as input two arrays of integers and swap their elements. If the length of the two arrays are not equal, the function should raise an AssertionError.
  
  def swap(arr1, arr2):
      assert len(arr1) == len(arr2)
      for i in range(len(arr1)):
          temp = arr1[i]
          arr1[i] = arr2[i]
          arr2[i] = temp
  
  assert swap([3, 5, 6, 9], [2, 4, 7, 8])==None
  assert swap([1, 3, 5], [2, 4, 6])==None
  assert swap([10], [20])==None
  assert swap([], [])==None
output: def swap(arr1, arr2):
      assert len(arr1) == len(arr2)
      for i in range(len(arr1)):
          temp = arr1[i]
          arr1[i] = arr2[i]
          arr2[i] = temp