code: @Override
  	protected boolean isCacheValid() {
  		return super.isCacheValid()
  				&& StringUtils.equals(cacheProperties.getProperty(JAWR_JS_GENERATOR_COFFEE_SCRIPT_LOCATION),
  						config.getProperty(JAWR_JS_GENERATOR_COFFEE_SCRIPT_LOCATION, DEFAULT_COFFEE_SCRIPT_JS_LOCATION))
  				&& StringUtils.equals(cacheProperties.getProperty(JAWR_JS_GENERATOR_COFFEE_SCRIPT_OPTIONS),
  						config.getProperty(JAWR_JS_GENERATOR_COFFEE_SCRIPT_OPTIONS, COFFEE_SCRIPT_DEFAULT_OPTIONS))
  				&& StringUtils.equals(cacheProperties.getProperty(JAWR_JS_GENERATOR_COFFEE_SCRIPT_JS_ENGINE),
  						config.getJavascriptEngineName(JAWR_JS_GENERATOR_COFFEE_SCRIPT_JS_ENGINE));
  	}
docs: /*
  (non-Javadoc)
  
  @see net.jawr.web.resource.bundle.generator.AbstractCachedGenerator#
  isCacheValid()