public static boolean isModifiedSince(long ifModifiedSince, Calendar lastModified) {
        return lastModified != null && isModifiedSince(ifModifiedSince, lastModified.getTimeInMillis());
    }
public static boolean isModifiedSince ( long ifModifiedSince , Calendar lastModified ) { return lastModified != null && isModifiedSince ( ifModifiedSince , lastModified . getTimeInMillis ( ) ) ; }
returns 'true' if 'lastModified' is after 'ifModifiedSince' (and both values are valid)