code: func (c *engineRPC) Close() error {
  	if c.client == nil {
  		return fmt.Errorf("No client to close")
  	}
  	if err := c.client.Close(); err != nil {
  		return fmt.Errorf("Close failed: %v", err)
  	}
  	c.client = nil
  	c.conn = nil
  	return nil
  }
docs: // Close closes an existing connection to the Seesaw Engine.