docs: private ModelNode resolveSubsystems(final List<ModelNode> extensions) {
  
          HostControllerLogger.ROOT_LOGGER.debug("Applying extensions provided by master");
          final ModelNode result = operationExecutor.installSlaveExtensions(extensions);
          if (!SUCCESS.equals(result.get(OUTCOME).asString())) {
              throw HostControllerLogger.ROOT_LOGGER.failedToAddExtensions(result.get(FAILURE_DESCRIPTION));
          }
          final ModelNode subsystems = new ModelNode();
          for (final ModelNode extension : extensions) {
              extensionRegistry.recordSubsystemVersions(extension.asString(), subsystems);
          }
          return subsystems;
      }