@CanIgnoreReturnValue
  public DirectoryEntry requireSymbolicLink(Path pathForException)
      throws NoSuchFileException, NotLinkException {
    requireExists(pathForException);
    if (!file().isSymbolicLink()) {
      throw new NotLinkException(pathForException.toString());
    }
    return this;
  }
Checks that this entry exists and links to a symbolic link, throwing an exception if not.

@return this
@throws NoSuchFileException if this entry does not exist
@throws NotLinkException if this entry does not link to a symbolic link
jimfs/src/main/java/com/google/common/jimfs/DirectoryEntry.java