input: Write a function to suggest an improvement for the given Python code for finding the sum of elements of a list. The original code is a for loop that iterates through each element of the list and accumulates the sum. The improved function should replace the for loop with a more efficient single line of code.
  
  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([-1, -2, -3, -4, -5])==-15
  assert sum_elements([])==0
  assert sum_elements([10, 20, 30, 100])==160
  assert sum_elements([0, 0, 0])==0
output: def sum_elements(arr):
      return sum(arr)