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: rpc.rs
    path of file: ./repos/hypercube/src
    
    the code of the file until where you have to start completion: //! The `rpc` module implements the HyperCube RPC interface.

use transaction_processor::{TransactionProcessor, TransactionProcessorError};
use bincode::deserialize;
use bs58;
use jsonrpc_core::*;
use jsonrpc_http_server::*;
use service::Service;
use signature::Signature;
use xpz_program_interface::account::Account;
use xpz_program_interface::pubkey::Pubkey;
use std::mem;
use std::net::{SocketAddr, UdpSocket};
use std::result;
use std::sync::atomic::{AtomicBool, Ordering};
use std::sync::Arc;
use std::thread::{self, sleep, Builder, JoinHandle};
use std::time::Duration;
use std::time::Instant;
use transaction::Transaction;
use qtc::request_airdrop;

pub const RPC_PORT: u16 = 8899;

pub 
    
    fn test_rpc_request_bad_signature() {
        let alice = Mint::new(10_000);
        let transaction_processor = TransactionProcessor::new(&alice);

        let mut io = MetaIoHandler::default();
        let rpc = RpcXpzImpl;
        io.extend_with(rpc.to_delegate());
        let req =
            r#"{"jsonrpc":"2.0","id":1,"method":"confirmTransaction","params":["a1b2c3d4e5"]}"#;
        let meta = Meta {
            request_processor: JsonRpcRequestProcessor::new(Arc::new(transaction_processor)),
            transactions_addr: SocketAddr::new(IpAddr::V4(Ipv4Addr::new(0, 0, 0, 0)), 0),
            faucet_addr: SocketAddr::new(IpAddr::V4(Ipv4Addr::new(0, 0, 0, 0)), 0),
        };

        let res = io.handle_request_sync(req, meta);
        let expected =
            r#"{"jsonrpc":"2.0","error":{"code":-32600,"message":"Invalid request"},"id":1}"#;
        let expected: Response =
            serde_json::from_str(expected).expect("expected response deserialization");

        let result: Response = serde_json::from_str(&res.expect("actual response"))
            .expect("actual response deserialization");
        assert_eq!(expected, result);
    }