public JmxClient(@NonNull JMXServiceURL connection_url,boolean lazy) throws IOException {
  jmxUrl=Optional.of(connection_url);
  conn_=null;
}

public JmxClient ( @ NonNull JMXServiceURL connection_url , boolean lazy ) throws IOException { jmxUrl = Optional . of ( connection_url ) ; conn_ = null ; }
create a new client , connecting to the specified url .
