input: Write a function to sort a list of numbers using the Insertion Sort algorithm. The function should take a list as input and return a sorted list. If the input list is empty, the function should return an empty list.
  
  def insertionSort(arr):
  	for i in range(1, len(arr)):
  		current = arr[i]
  		j = i - 1
  		while j >= 0 and arr[j] > current:
  			arr[j + 1] = arr[j]
  			j -= 1
  		arr[j + 1] = current
  	return arr
  
  assert insertionSort([2, 4, 7, 3, 8, 6, 1]) == [1, 2, 3, 4, 6, 7, 8]
  assert insertionSort([5, 4, 3, 2, 1]) == [1, 2, 3, 4, 5]
  assert insertionSort([]) == []
  assert insertionSort([10, -1, 3]) == [-1, 3, 10]
  assert insertionSort([1]) == [1]
output: def insertionSort(arr):
  	for i in range(1, len(arr)):
  		current = arr[i]
  		j = i - 1
  		while j >= 0 and arr[j] > current:
  			arr[j + 1] = arr[j]
  			j -= 1
  		arr[j + 1] = current
  	return arr