code: def _build_tree(self, actor, content):
          
          depth = actor.depth
          row = ""
          for i in xrange(depth - 1):
              row += "| "
          if depth > 0:
              row += "|-"
          name = actor.name
          if name != actor.__class__.__name__:
              name = actor.__class__.__name__ + " '" + name + "'"
          row += name
          quickinfo = actor.quickinfo
          if quickinfo is not None:
              row += " [" + quickinfo + "]"
          content.append(row)
  
          if isinstance(actor, ActorHandler):
              for sub in actor.actors:
                  self._build_tree(sub, content)
docs: Builds the tree for the given actor.
  
          :param actor: the actor to process
          :type actor: Actor
          :param content: the rows of the tree collected so far
          :type content: list