code: func (r Provisioning_Maintenance_Window) GetMaintenanceWindows(beginDate *datatypes.Time, endDate *datatypes.Time, locationId *int, slotsNeeded *int) (resp []datatypes.Provisioning_Maintenance_Window, err error) {
  	params := []interface{}{
  		beginDate,
  		endDate,
  		locationId,
  		slotsNeeded,
  	}
  	err = r.Session.DoRequest("SoftLayer_Provisioning_Maintenance_Window", "getMaintenanceWindows", params, &r.Options, &resp)
  	return
  }
docs: // This method returns a list of available maintenance windows