code: def extend(self, *iterables):
          
  
          for value in iterables:
              list.extend(self, value)
          return self
docs: Add all values of all iterables at the end of the list
  
          Args:
              iterables: iterable which content to add at the end
  
          Example:
  
              >>> from ww import l
              >>> lst = l([])
              >>> lst.extend([1, 2])
              [1, 2]
              >>> lst
              [1, 2]
              >>> lst.extend([3, 4]).extend([5, 6])
              [1, 2, 3, 4, 5, 6]
              >>> lst
              [1, 2, 3, 4, 5, 6]