input: from typing import List
  from typing import Tuple
  
  def split_equal_sum(arr: List[int]) -> Tuple[List[int], List[int]]:
      """ Splits the given array into two subarrays such that the sum of elements in the two subarrays are equal.
      If such a split is possible, returns the two subarrays. Otherwise returns None.
      >>> split_equal_sum([1, 2, 3, 4])
      [[1, 4], [2, 3]]
      >>> split_equal_sum([1, 2, 3, 7])
      None
      """
      total_sum = sum(arr)
      if total_sum % 2 != 0:
          return None
      
      half_sum = total_sum // 2
      current_sum = 0
      for i in range(len(arr)):
          current_sum += arr[i]
          if current_sum == half_sum:
              return [arr[:i+1], arr[i+1:]]
          if current_sum > half_sum:
              return None
      return None
  
output:     total_sum = sum(arr)
      if total_sum % 2 != 0:
          return None
      
      half_sum = total_sum // 2
      current_sum = 0
      for i in range(len(arr)):
          current_sum += arr[i]
          if current_sum == half_sum:
              return [arr[:i+1], arr[i+1:]]
          if current_sum > half_sum:
              return None
      return None