-preprocessmatchers FILE-SPEC

	String							DEFAULT_PREPROCESSS_MATCHERS				= "!*.(jpg|jpeg|jif|jfif|jp2|jpx|j2k|j2c|fpx|png|gif|swf|doc|pdf|tiff|tif|raw|bmp|ppm|pgm|pbm|pnm|pfm|webp|zip|jar|gz|tar|tgz|exe|com|bin|mp[0-9]|mpeg|mov|):i, *";


private Instructions getPreProcessMatcher(Map<String,String> extra) {
	if (defaultPreProcessMatcher == null) {
		defaultPreProcessMatcher = new Instructions(getProperty(PREPROCESSMATCHERS,
				Constants.DEFAULT_PREPROCESSS_MATCHERS));
	}
	if (extra == null)
		return defaultPreProcessMatcher;

	String additionalMatchers = extra.get(PREPROCESSMATCHERS);
	if (additionalMatchers == null)
		return defaultPreProcessMatcher;

	Instructions specialMatcher = new Instructions(additionalMatchers);
	specialMatcher.putAll(defaultPreProcessMatcher);
	return specialMatcher;
}