code: def getsetitem(self, key, klass, args=None, kwdargs=None):
          
  
          with self.lock:
              if key in self:
                  return self.getitem(key)
  
              # Instantiate value.
              if not args:
                  args = []
              if not kwdargs:
                  kwdargs = {}
              value = klass(*args, **kwdargs)
  
              self.setitem(key, value)
              return value
docs: This is similar to setdefault(), except that the new value is
          created by instantiating _klass_.  This prevents you from having
          to create an object and initialize it and then throw it away if
          there is already a dictionary item of that type.