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: addition.rs
    path of file: ./repos/rust/examples
    
    the code of the file until where you have to start completion: use std::error::Error;
use std::fs::File;
use std::io::Read;
use std::path::Path;
use std::result::Result;
use tensorflow::Code;
use tensorflow::Graph;
use tensorflow::ImportGraphDefOptions;
use tensorflow::Session;
use tensorflow::SessionOptions;
use tensorflow::SessionRunArgs;
use tensorflow::Status;
use tensorflow::Tensor;

#[cfg_attr(feature = "examples_system_alloc", global_allocator)]
#[cfg(feature = "examples_system_alloc")]
static ALLOCATOR: std::alloc::System = std::alloc::System;

fn main() -> Result<(), Box<dyn Error>> {
    let filename = "examples/addition/model.pb"; // z = x + y
    if !Path::new(filename).exists() {
        return Err(Box::new(
            Status::new_set(
                Code::NotFound,
                &format!(
                    "Run 'python addition.py' to generate {} \
                     and try again.",
                    filename
                ),
            )
            .unwrap(),
        ));
    }

    // Create input variables f
    
fn main() -> Result<(), Box<dyn Error>> {
    let filename = "examples/addition/model.pb"; // z = x + y
    if !Path::new(filename).exists() {
        return Err(Box::new(
            Status::new_set(
                Code::NotFound,
                &format!(
                    "Run 'python addition.py' to generate {} \
                     and try again.",
                    filename
                ),
            )
            .unwrap(),
        ));
    }

    // Create input variables for our addition
    let mut x = Tensor::new(&[1]);
    x[0] = 2i32;
    let mut y = Tensor::new(&[1]);
    y[0] = 40i32;

    // Load the computation graph defined by addition.py.
    let mut graph = Graph::new();
    let mut proto = Vec::new();
    File::open(filename)?.read_to_end(&mut proto)?;
    graph.import_graph_def(&proto, &ImportGraphDefOptions::new())?;
    let session = Session::new(&SessionOptions::new(), &graph)?;

    // Run the graph.
    let mut args = SessionRunArgs::new();
    args.add_feed(&graph.operation_by_name_required("x")?, 0, &x);
    args.add_feed(&graph.operation_by_name_required("y")?, 0, &y);
    let z = args.request_fetch(&graph.operation_by_name_required("z")?, 0);
    session.run(&mut args)?;

    // Check our results.
    let z_res: i32 = args.fetch(z)?[0];
    println!("{:?}", z_res);

    Ok(())
}