code: func (c *CloudWatch) DescribeAlarmHistory(input *DescribeAlarmHistoryInput) (*DescribeAlarmHistoryOutput, error) {
  	req, out := c.DescribeAlarmHistoryRequest(input)
  	return out, req.Send()
  }
docs: // DescribeAlarmHistory API operation for Amazon CloudWatch.
  //
  // Retrieves the history for the specified alarm. You can filter the results
  // by date range or item type. If an alarm name is not specified, the histories
  // for all alarms are returned.
  //
  // CloudWatch retains the history of an alarm even if you delete the alarm.
  //
  // Returns awserr.Error for service API and SDK errors. Use runtime type assertions
  // with awserr.Error's Code and Message methods to get detailed information about
  // the error.
  //
  // See the AWS API reference guide for Amazon CloudWatch's
  // API operation DescribeAlarmHistory for usage and error information.
  //
  // Returned Error Codes:
  //   * ErrCodeInvalidNextToken "InvalidNextToken"
  //   The next token specified is invalid.
  //
  // See also, https://docs.aws.amazon.com/goto/WebAPI/monitoring-2010-08-01/DescribeAlarmHistory