code: @Override
      public boolean isCache() {
          return engine.getConfiguration().getBooleanPropertyValue(EngineConfigurationKey.TEMPLATE_CACHE_ENABLED)
                  && !engine.getConfiguration().getBooleanPropertyValue(EngineConfigurationKey.DEBUG_MODE)
                  && super.isCache();
      }
docs: Returns true, if the cache of the {@link MustacheEngine} is enabled and the debug mode is disabled. Also Spring's
  view resolution caching must be enabled.