@Override
   public boolean renameTo(File dest) {
      // implementing this based on the current storage structure is complex and very expensive.
      // a redesign is nessesary, especially must be avoid storing paths as key
      // maybe file name + reference to the parent in metadata and as key is used a uuid, so movements or renames
      // are only affected on the current file. metadata should also contain list of uuids of the corresponding data chunks
      throw new UnsupportedOperationException("Not implemented");
   }
@Test(expectedExceptions = UnsupportedOperationException.class)
   public void testRenameTo(){
      fs.getFile("file.txt").renameTo(null);
   }