code: def modify_attribute(self, attribute, value):
          
          return self.connection.modify_instance_attribute(self.id, attribute,
                                                           value)
docs: Changes an attribute of this instance
  
          :type attribute: string
          :param attribute: The attribute you wish to change.
                            AttributeName - Expected value (default)
                            instanceType - A valid instance type (m1.small)
                            kernel - Kernel ID (None)
                            ramdisk - Ramdisk ID (None)
                            userData - Base64 encoded String (None)
                            disableApiTermination - Boolean (true)
                            instanceInitiatedShutdownBehavior - stop|terminate
                            rootDeviceName - device name (None)
  
          :type value: string
          :param value: The new value for the attribute
  
          :rtype: bool
          :return: Whether the operation succeeded or not