@Override
 public void set(Input value) {
   List<Input> binds = Lists.newArrayList(config.getBinds(bindUri));
   if (value == null) {
     if (position < binds.size()) {
       binds.remove(position);
     }
   } else {
     if (position < binds.size()) {
       binds.set(position, value);
     } else {
       binds.add(value);
     }
   }
   config.setBinds(bindUri, binds);
 }
 @Override
 public Input get() {
   return Iterators.get(config.getBinds(bindUri).iterator(), position, null);
 }