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: main.rs
    path of file: ./repos/minijinja/examples/render-template/src
    
    the code of the file until where you have to start completion: //! This is a small example program that evaluates an expression and returns
//! the result on stdout in JSON format.  The values provided to the script
//! are the environment variables in the `env` dict.
use std::fs;
use std::path::PathBuf;

use argh::FromArgs;
use minijinja::Environment;

/// A small application that renders a MiniJinja template.
#[derive(FromArgs)]
struct
    
fn execute() -> Result<(), Box<dyn std::error::Error>> {
    let cli: Cli = argh::from_env();

    let mut env = Environment::new();
    let source = fs::read_to_string(&cli.template)?;
    let name = cli.template.file_name().unwrap().to_str().unwrap();
    env.add_template(name, &source)?;

    let ctx: serde_json::Value = serde_json::from_slice(&fs::read(&cli.context)?)?;

    let tmpl = env.get_template(name).unwrap();
    println!("{}", tmpl.render(ctx)?);

    Ok(())
}