input: Write a function to implement the Insertion Sort algorithm to sort a list of numbers in ascending order. The function should take a list as input and return the sorted 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
  
  if __name__ == '__main__':
  	arr = [2, 4, 7, 3, 8, 6, 1]
  	print(insertionSort(arr))
  assert insertionSort([5, 3, 8, 4, 6]) == [3, 4, 5, 6, 8]
  assert insertionSort([1, 2, 3, 4, 5]) == [1, 2, 3, 4, 5]
  assert insertionSort([9, 7, 5, 3, 1]) == [1, 3, 5, 7, 9]
  assert insertionSort([]) == []
  assert insertionSort([3, 3, 3, 3, 3]) == [3, 3, 3, 3, 3]
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