You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: client.rs
    path of file: ./repos/tonic/examples/src/codec_buffers
    
    the code of the file until where you have to start completion: //! A HelloWorld example that uses a custom codec instead of the default Prost codec.
//!
//! Generated code is the output of codegen as defined in the `examples/build.rs` file.
//! The generation is the one with .codec_path("crate::common::SmallBufferCodec")
//! The generated co
    
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let mut client = GreeterClient::connect("http://[::1]:50051").await?;

    let request = tonic::Request::new(HelloRequest {
        name: "Tonic".into(),
    });

    let response = client.say_hello(request).await?;

    println!("RESPONSE={:?}", response);

    Ok(())
}