import ( "bufio" "net" ) func main() { conn, err := net.Dial("tcp", "localhost:12345") if err != nil { panic(err) } rw := bufio.NewReadWriter(bufio.NewReader(conn), bufio.NewWriter(conn)) data := []byte("Hello, world!") _, err = rw.Write(data) if err != nil { panic(err) } err = rw.Flush() if err != nil { panic(err) } conn.Close() }In this example, we create a new `ReadWriter` object using a `bufio.NewReader` and `bufio.NewWriter`. We then use the `Write()` method to send a message to the server and the `Flush()` method to ensure that the entire message is sent. Finally, we close the connection. This code uses the `net` package, but the `bufio` package is where the `ReadWriter` type and the `Write()` and `Flush()` methods are defined. Overall, the `bufio` package provides useful functionality for managing input and output streams. It can be used in various scenarios where streaming data is required, such as network communication or file processing.