code: SchemaFuture installHandlers(XMLReader in, SchemaReceiverImpl sr) {
      Handler h = new Handler(sr);
      in.setContentHandler(h);
      return h;
    }
docs: Installs the schema handler on the reader.
  
  @param in The reader.
  @param sr The schema receiver.
  @return The installed handler that implements also SchemaFuture.