input: Write a function to improve the following Python code for finding the sum of elements of a list. The improvement should be made in one line of code. 
  
  ### Original Code:
  def sum_elements(arr):
      sum_value = 0
      for num in arr:
          sum_value += num
      return sum_value
  
  ### Improved Code:
  def sum_elements(arr):
      return sum(arr) # return sum of elements of arr with one line of code.
output: def sum_elements(arr):
      return sum(arr)