input: Write a function to implement the insertion sort algorithm that sorts a list in ascending order. The function should modify the list in place and return the sorted list.
  
  def insertion_sort(list):
      for i in range(1, len(list)):
          key = list[i]
          j = i - 1
          while j >= 0 and key < list[j]:
              list[j + 1] = list[j]
              j -= 1
          list[j + 1] = key
      return list
  
  assert insertion_sort([3, 4, 2, 1, 5])==[1, 2, 3, 4, 5]
  assert insertion_sort([5, 3, 4, 1, 2])==[1, 2, 3, 4, 5]
  assert insertion_sort([1, 2, 3, 4, 5])==[1, 2, 3, 4, 5]
  assert insertion_sort([2, 3, 1])==[1, 2, 3]
  assert insertion_sort([])==[]
output: def insertion_sort(list):
      for i in range(1, len(list)):
          key = list[i]
          j = i - 1
          while j >= 0 and key < list[j]:
              list[j + 1] = list[j]
              j -= 1
          list[j + 1] = key
      return list