input: Write a function to sort an array in ascending order using the built-in sort method in Python. Return the sorted 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([4, 2, 1, 3, 5]) == [1, 2, 3, 4, 5]
  assert sort_ascending([]) == []
  assert sort_ascending([7]) == [7]
  assert sort_ascending([9, 9, 9, 9]) == [9, 9, 9, 9]
output: def sort_ascending(array):
    array.sort()
    return array