code: private void send()
  		throws IOException, SQLException
  	{
  
  		this.indexWriter.write(articleIndex);
  		this.indexWriter.write(revisionIndex);
  		this.indexWriter.write(chronoIndex);
  	}
docs: Checks whether the AbstractIndex classes have output available and
  forward them to the output writer.
  
  @throws IOException
  if an error occurred while writing the output
  @throws SQLException
  if an error occurred while accessing the database