code: def copy(self, o=None):
          
          if o is None: o = self.__class__(self.project)
          o.scripts = [s.copy() for s in self.scripts]
          o.variables = dict((n, v.copy()) for (n, v) in self.variables.items())
          o.lists = dict((n, l.copy()) for (n, l) in self.lists.items())
          o.costumes = [c.copy() for c in self.costumes]
          o.sounds = [s.copy() for s in self.sounds]
          o.costume_index = self.costume_index
          o.volume = self.volume
          return o
docs: Return a new instance, deep-copying all the attributes.