input: Write a function to suggest an improvement for the given Python code that finds the sum of elements of a list. The input code should be improved to make it more concise and efficient. Provide the improved code and test cases to demonstrate its functionality.
  assert sum_elements([1, 2, 3, 4])==10
  assert sum_elements([5, 10, 15, 20])==50
  assert sum_elements([-1, 0, 1])==0
  assert sum_elements([])==0
output: def sum_elements(lst):
      return sum(lst)