public static void removeFilePermission(final Path path,
                                            final PosixFilePermission... posixFilePermission) throws IOException {
        final Set<PosixFilePermission> filePermissions = Files.getPosixFilePermissions(path);
        final Set<PosixFilePermission> newPermissions = new HashSet<>(filePermissions);
        newPermissions.removeAll(Arrays.asList(posixFilePermission));
        Files.setPosixFilePermissions(path, newPermissions);
    }
Similar to the unix touch command. Sets the last modified time to now if the file
exists else, creates the file

@throws IOException
stroom-util/src/main/java/stroom/util/io/FileUtil.java