input: Write a python function to find the pair of elements in an array that have the maximum product.
  assert max_pair_product([1, 2, 3, 4, 5]) == (20, [4, 5])
  assert max_pair_product([0, -1, 3, 100, 70, 50]) == (7000, [100, 70])
  assert max_pair_product([5, 2, 8, 9, 7, 4]) == (72, [8, 9])
output: def max_pair_product(arr):
      if len(arr) < 2:
          return None
  
      max_product = float('-inf')
      pair = []
  
      for i in range(len(arr)):
          for j in range(i + 1, len(arr)):
              product = arr[i] * arr[j]
              if product > max_product:
                  max_product = product
                  pair = [arr[i], arr[j]]
  
      return max_product, pair