148         if (!lint.isSuppressed(LintCategory.PREVIEW)) {
 149             previewHandler.report(null,
 150                     Warnings.PreviewFeatureUseClassfile(classfile, majorVersionToSource.get(majorVersion).name));
 151         }
 152     }
 153 
 154     /**
 155      * Are preview features enabled?
 156      * @return true, if preview features are enabled.
 157      */
 158     public boolean isEnabled() {
 159         return enabled;
 160     }
 161 
 162     /**
 163      * Is given feature a preview feature?
 164      * @param feature the feature to be tested.
 165      * @return true, if given feature is a preview feature.
 166      */
 167     public boolean isPreview(Feature feature) {




 168         //Note: this is a backdoor which allows to optionally treat all features as 'preview' (for testing).
 169         //When real preview features will be added, this method can be implemented to return 'true'
 170         //for those selected features, and 'false' for all the others.
 171         return forcePreview;
 172     }
 173 
 174     /**
 175      * Generate an error key which captures the fact that a given preview feature could not be used
 176      * due to the preview feature support being disabled.
 177      * @param feature the feature for which the diagnostic has to be generated.
 178      * @return the diagnostic.
 179      */
 180     public Error disabledError(Feature feature) {
 181         Assert.check(!isEnabled());
 182         return feature.isPlural() ?
 183                 Errors.PreviewFeatureDisabledPlural(feature.nameFragment()) :
 184                 Errors.PreviewFeatureDisabled(feature.nameFragment());
 185     }
 186 
 187     /**

 148         if (!lint.isSuppressed(LintCategory.PREVIEW)) {
 149             previewHandler.report(null,
 150                     Warnings.PreviewFeatureUseClassfile(classfile, majorVersionToSource.get(majorVersion).name));
 151         }
 152     }
 153 
 154     /**
 155      * Are preview features enabled?
 156      * @return true, if preview features are enabled.
 157      */
 158     public boolean isEnabled() {
 159         return enabled;
 160     }
 161 
 162     /**
 163      * Is given feature a preview feature?
 164      * @param feature the feature to be tested.
 165      * @return true, if given feature is a preview feature.
 166      */
 167     public boolean isPreview(Feature feature) {
 168         if (feature == Feature.SWITCH_EXPRESSION ||
 169             feature == Feature.SWITCH_MULTIPLE_CASE_LABELS ||
 170             feature == Feature.SWITCH_RULE)
 171             return true;
 172         //Note: this is a backdoor which allows to optionally treat all features as 'preview' (for testing).
 173         //When real preview features will be added, this method can be implemented to return 'true'
 174         //for those selected features, and 'false' for all the others.
 175         return forcePreview;
 176     }
 177 
 178     /**
 179      * Generate an error key which captures the fact that a given preview feature could not be used
 180      * due to the preview feature support being disabled.
 181      * @param feature the feature for which the diagnostic has to be generated.
 182      * @return the diagnostic.
 183      */
 184     public Error disabledError(Feature feature) {
 185         Assert.check(!isEnabled());
 186         return feature.isPlural() ?
 187                 Errors.PreviewFeatureDisabledPlural(feature.nameFragment()) :
 188                 Errors.PreviewFeatureDisabled(feature.nameFragment());
 189     }
 190 
 191     /**