input: Write a function to check if an array contains consecutive numbers.
  assert check_array_for_consecutive([2, 3, 4, 5, 6]) == True
  assert check_array_for_consecutive([1, 2, 4, 5, 6]) == False
  assert check_array_for_consecutive([10, 11, 12, 13, 15]) == False
  assert check_array_for_consecutive([5, 6, 7, 8, 9, 10]) == True
output: def check_array_for_consecutive(arr):
      if not arr:
          return False
      arr_sorted = sorted(arr)
      for i in range(len(arr_sorted) - 1):
          if arr_sorted[i] + 1 != arr_sorted[i + 1]:
              return False
      return True