input: Write a function to sort an array in ascending order using Python.
  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([5, 3, 8, 6, 7, 2])==[2, 3, 5, 6, 7, 8]
  assert sort_ascending([1, 2, 3, 4, 5])==[1, 2, 3, 4, 5]
  assert sort_ascending([])==[]
  assert sort_ascending([100, 99, 98, 97])==[97, 98, 99, 100]
output: def sort_ascending(array):
    array.sort()
    return array