code: def forward(*args, **kwargs):
          
          self, cmd = args[:2]
  
          # It's also possible to invoke another command which might or
          # might not have a callback.
          if not isinstance(cmd, Command):
              raise TypeError('Callback is not a command.')
  
          for param in self.params:
              if param not in kwargs:
                  kwargs[param] = self.params[param]
  
          return self.invoke(cmd, **kwargs)
docs: Similar to :meth:`invoke` but fills in default keyword
          arguments from the current context if the other command expects
          it.  This cannot invoke callbacks directly, only other commands.