input: Write a function to swap the elements of two arrays of integers. The function should ensure that both arrays are of the same length before performing the swap. The arrays should be swapped element by element. If the arrays are not of the same length, the function should raise an AssertionError.
  assert swap([3, 5, 6, 9], [2, 4, 7, 8])==([2, 4, 7, 8], [3, 5, 6, 9])
  assert swap([1, 2, 3], [4, 5, 6])==([4, 5, 6], [1, 2, 3])
  assert swap([], [])==([], [])
  assert swap([1], [2])==([2], [1])
  assert swap([1, 2], [3, 4])==([3, 4], [1, 2])
output: def swap(arr1, arr2):
      assert len(arr1) == len(arr2), "Arrays must be of the same length"
      for i in range(len(arr1)):
          arr1[i], arr2[i] = arr2[i], arr1[i]
      return arr1, arr2