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: token_freeze_v1.rs
    path of file: ./repos/darkfi/src/contract/money/src/client
    
    the code of the file until where you have to start completion: /* This file is part of DarkFi (https://dark.fi)
 *
 * Copy
    
    pub fn build(&self) -> Result<TokenFreezeCallDebris> {
        info!("Building Money::TokenFreezeV1 contract call");

        // For the TokenFreeze call, we just need to produce a valid signature,
        // and enforce the correct derivation inside ZK.
        let prover_witnesses = vec![
            // Token attributes
            Witness::Base(Value::known(self.token_attrs.auth_parent.inner())),
            Witness::Base(Value::known(self.token_attrs.blind.inner())),
            // Secret key used by mint
            Witness::Base(Value::known(self.mint_keypair.secret.inner())),
        ];

        let mint_pubkey = self.mint_keypair.public;
        let token_id = self.token_attrs.to_token_id();

        let public_inputs = vec![mint_pubkey.x(), mint_pubkey.y(), token_id.inner()];
        //darkfi::zk::export_witness_json("witness.json", &prover_witnesses, &public_inputs);

        let circuit = ZkCircuit::new(prover_witnesses, &self.freeze_zkbin);
        let proof = Proof::create(&self.freeze_pk, &[circuit], &public_inputs, &mut OsRng)?;

        let params = MoneyTokenFreezeParamsV1 { mint_public: self.mint_keypair.public, token_id };
        let debris = TokenFreezeCallDebris { params, proofs: vec![proof] };
        Ok(debris)
    }