input: Write a function to sort an array in ascending order using Python. The function should take an array as input and 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([7, 4, 1, 5, 8, 2])==[1, 2, 4, 5, 7, 8]
  assert sort_ascending([])==[]
  assert sort_ascending([5, 3, 8, 4, 2])==[2, 3, 4, 5, 8]
output: def sort_ascending(array):
    array.sort()
    return array