input: Write a function to provide a suggestion to improve a given Python code for finding the sum of elements of a list by reducing it to a single line of code. If the given input code is already optimal, return the same code.
  assert sum_elements([1, 2, 3, 4])==10
  assert sum_elements([-1, -2, -3, -4])==-10
  assert sum_elements([0, 0, 0, 0])==0
  assert sum_elements([])==0
output: def sum_elements(lst):
      return sum(lst)