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/risc0/examples/groth16-verifier/src
    
    the code of the file until where you have to start completion: // Copyright 2024 RISC Zero, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use groth16_verifier_methods::{GROTH16_VERIFIER_ELF, GR
    
fn main() {
    // verification_key, proof and public witness generated by SnarkJS using Groth16 over BN254
    // (https://docs.circom.io/getting-started/proving-circuits/)
    let proof: ProofJson = serde_json::from_str(PROOF).unwrap();
    let public_inputs = PublicInputsJson {
        values: serde_json::from_str(PUBLIC_INPUTS).unwrap(),
    };
    let verifying_key: VerifyingKeyJson = serde_json::from_str(VERIFICATION_KEY).unwrap();

    // we initialize a Groth16 verifier from the josn material generated by SnarkJS
    let verifier = Verifier::from_json(proof, public_inputs, verifying_key).unwrap();

    // groth16 proof verification
    verifier.verify().unwrap();

    // we configure an Executor with the groth16 verifier
    let env = ExecutorEnv::builder()
        .write(&verifier)
        .unwrap()
        .build()
        .unwrap();

    // we run the prover to generate a receipt of correct verification
    let receipt = default_prover().prove(env, GROTH16_VERIFIER_ELF).unwrap();

    // we verify the final receipt
    receipt.verify(GROTH16_VERIFIER_ID).unwrap();

    // we check that what committed into the journal matches with the input
    let committed_digest: Digest = receipt.journal.decode().unwrap();

    let mut hasher = Sha256::new();
    hasher.update(verifier.encoded_pvk);
    hasher.update(verifier.encoded_proof);
    hasher.update(verifier.encoded_prepared_inputs);
    let expected_digest = hasher.finalize();
    let expected_digest = Digest::try_from(expected_digest.as_slice()).unwrap();

    assert_eq!(committed_digest, expected_digest);

    println!("Verification: OK!");
}