input: Write a function to sort an array in ascending order using Python's built-in sort method. The function should return the sorted array. If the input array is empty, it should return an empty array.
  def sort_ascending(array):
    array.sort()
    return array
  
  assert sort_ascending([10, 3, 9, 1, 15, 2])==[1, 2, 3, 9, 10, 15]
  assert sort_ascending([])==[]
  assert sort_ascending([5])==[5]
  assert sort_ascending([3, 2, 1])==[1, 2, 3]
  assert sort_ascending([1, 2, 3, 4, 5])==[1, 2, 3, 4, 5]
output: def sort_ascending(array):
    array.sort()
    return array