code: def repeat(self, n=2, oscillate=False, callback=None):
          
          colorlist = ColorList()
          colors = ColorList.copy(self)
          for i in _range(n):
              colorlist.extend(colors)
              if oscillate: colors = colors.reverse()
              if callback: colors = callback(colors)
  
          return colorlist
docs: Returns a list that is a repetition of the given list.
  
          When oscillate is True,
          moves from the end back to the beginning,
          and then from the beginning to the end, and so on.