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: bench.rs
    path of file: ./repos/argmin/crates/finitediff/benches
    
    the code of the file until where you have to start completion: // Copyright 2018-2024 argmin developers
//
// Licensed under th
    
    fn forward_hessian_nograd_sparse_vec_f64(b: &mut Bencher) {
        let x = vec![1.0f64; MASSIVENESS];
        b.iter(|| {
            let indices = vec![[1, 2], [23, 23], [128, 8]];
            black_box(x.forward_hessian_nograd_sparse(&cost_vec_f64, indices));
        });
    }