code: func (cli *OpsGenieHeartbeatClient) Enable(req heartbeat.EnableHeartbeatRequest) (*heartbeat.EnableHeartbeatResponse, error) {
  	var response heartbeat.HeartbeatMetaResponseV2
  
  	err := cli.sendPostRequest(&req, &response)
  
  	if err != nil {
  		return nil, err
  	}
  
  	var result heartbeat.EnableHeartbeatResponse
  	result.Status = "successful"
  	result.Code = 200
  	return &result, nil
  }
docs: // Enable method enables an heartbeat at OpsGenie.