code: func (c *ELB) WaitUntilInstanceDeregistered(input *DescribeInstanceHealthInput) error {
  	return c.WaitUntilInstanceDeregisteredWithContext(aws.BackgroundContext(), input)
  }
docs: // WaitUntilInstanceDeregistered uses the Elastic Load Balancing API operation
  // DescribeInstanceHealth to wait for a condition to be met before returning.
  // If the condition is not met within the max attempt window, an error will
  // be returned.