com_baeldung_selector_NioEchoLiveTest_java
com.baeldung.selector.EchoClient
public static EchoClient start() {         if (instance == null)             instance = new EchoClient();          return instance;

 -> java.nio.channels.SocketChannel.open(java.net.SocketAddress): java.nio.channels.SocketChannel -> java.security.AccessController.doPrivileged(java.security.PrivilegedAction): java.lang.Object -> java.lang.System.getProperty(java.lang.String): java.lang.String -> java.lang.String.equals(java.lang.Object): boolean -> java.lang.String.equals(java.lang.Object): boolean -> java.lang.Class.forName(java.lang.String): java.lang.Class -> java.lang.System.loadLibrary(java.lang.String): void -> java.lang.Class.getConstructor(java.lang.Class[]): java.lang.reflect.Constructor -> java.lang.reflect.Constructor.newInstance(java.lang.Object[]): java.lang.Object -> java.util.Set.add(java.lang.Object): boolean -> java.util.Set.of(java.lang.Object,java.lang.Object,java.lang.Object): java.util.Set -> java.util.Set.addAll(java.util.Collection): boolean -> java.util.Collections.unmodifiableSet(java.util.Set): java.util.Set -> java.io.IOException.printStackTrace(): void