input: Write a function to print out the elements from the given lists in a nested loop format, with each combination of elements printed on a new line. The function should take a single list of lists as input and perform nested loops to iterate through each element in each list.
  
  def nested_print(lists):
      for x in lists[0]:
          for y in lists[1]:
              for z in lists[2]:
                  print(x, y, z)
  
  assert nested_print([[1,2,3], [4,5,6], [7,8,9]])
  assert nested_print([[2,4,6], [3,6,9], [1,8]])
  assert nested_print([[1], [1], [1]])
output: def nested_print(lists):
      for x in lists[0]:
          for y in lists[1]:
              for z in lists[2]:
                  print(x, y, z)