code: def cast_in(self, element):
          
          if _debug: Any._debug("cast_in %r", element)
  
          t = TagList()
          if isinstance(element, Atomic):
              tag = Tag()
              element.encode(tag)
              t.append(tag)
          elif isinstance(element, AnyAtomic):
              tag = Tag()
              element.value.encode(tag)
              t.append(tag)
          else:
              element.encode(t)
  
          self.tagList.extend(t.tagList)
docs: encode the element into the internal tag list.