@CanIgnoreReturnValue
  public PathSubject isNotSameFileAs(String path) throws IOException {
    if (Files.isSameFile(actual, toPath(path))) {
      failWithActual("expected not to be same file as", path);
    }
    return this;
  }
Asserts that the path does not resolve to the same file as the given path.
jimfs/src/test/java/com/google/common/jimfs/PathSubject.java