code: func (r Account) GetDiskUsageMetricImageByDate(startDateTime *datatypes.Time, endDateTime *datatypes.Time) (resp datatypes.Container_Account_Graph_Outputs, err error) {
  	params := []interface{}{
  		startDateTime,
  		endDateTime,
  	}
  	err = r.Session.DoRequest("SoftLayer_Account", "getDiskUsageMetricImageByDate", params, &r.Options, &resp)
  	return
  }
docs: // Returns a disk usage image based on disk usage specified by the input parameters.