input: Write a function to improve the provided code for finding the sum of elements of a list. The original function iterates through the list and accumulates the sum. Your function should achieve the same result using a more concise approach.
  
  ### Input:
  def sum_elements(arr):
      sum_value = 0
      for num in arr:
          sum_value += num
      return sum_value
  
  ### Output:
  def sum_elements(arr):
      return sum(arr) # return sum of elements of arr with one line of code.
  
  assert sum_elements([1, 2, 3, 4, 5]) == 15
  assert sum_elements([0, 0, 0, 0]) == 0
  assert sum_elements([-1, -2, -3, -4, -5]) == -15
  assert sum_elements([]) == 0
  assert sum_elements([10]) == 10
output: def sum_elements(arr):
      return sum(arr)