Would it make sense to avoid the cost of compiling the pattern every time by declaring a constant `IS_DISK_REL_PREFIX_PATTERN` [Pattern](http://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html) and doing something like
```
public boolean apply(RESTLink link) {
  return IS_DISK_REL_PREFIX_PATTERN.matcher(link.getRel()).matches();
}
```

Also, just out of curiosity: how does REL_PREFIX following by numbers mean "it's a disk"? If the REL_PREFIX is unique to disks, should it perhaps be called DISK_REL_PREFIX or so instead?