Decorate abstract classes as abstract

src/settings/controllers/SettingController.ts

@@ -25,7 +25,7 @@ import { SettingLevel } from "../SettingLevel";
  * This is not intended to replace the functionality of a SettingsHandler, it is only
  * intended to handle environmental factors for specific settings.
  */
-export default class SettingController {
+export default abstract class SettingController {
     /**
      * Gets the overridden value for the setting, if any. This must return null if the
      * value is not to be overridden, otherwise it must return the new value.

src/settings/handlers/SettingsHandler.ts

@@ -19,7 +19,7 @@ limitations under the License.
  * Represents the base class for all level handlers. This class performs no logic
  * and should be overridden.
  */
-export default class SettingsHandler {
+export default abstract class SettingsHandler {
     /**
      * Gets the value for a particular setting at this level for a particular room.
      * If no room is applicable, the roomId may be null. The roomId may not be