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: consumer.rs
    path of file: ./repos/kafka-rust/tests/integration/consumer_producer
    
    the code of the file until where you have to start completion: use super::*;

use kafka::error;
use kafka::producer::Record;

/// Tests that consuming one message works
#[test]
fn test_consumer_poll() {
    tracing_subscriber::fmt::try_init();

    // poll once to set a position in the topic
    let mut consumer = test_consumer();
    let mut messages = consumer.poll().unwrap();
    assert!(
        messages.is_empty(),
        "messages was not empty: {:?}",
        messages
    );

    // send a message and then poll it and ensure it is the correct message
    let correct_message_contents = "test_consumer_poll".as_bytes();
    let mut producer = test_producer();
    producer
        .send(&Record::from_value(
            TEST_TOPIC_NAME,
            correct_message_contents,
        ))
        .unwrap();

    messages = consumer.poll().unwrap();
    let mut 
    
fn test_consumer_poll() {
    tracing_subscriber::fmt::try_init();

    // poll once to set a position in the topic
    let mut consumer = test_consumer();
    let mut messages = consumer.poll().unwrap();
    assert!(
        messages.is_empty(),
        "messages was not empty: {:?}",
        messages
    );

    // send a message and then poll it and ensure it is the correct message
    let correct_message_contents = "test_consumer_poll".as_bytes();
    let mut producer = test_producer();
    producer
        .send(&Record::from_value(
            TEST_TOPIC_NAME,
            correct_message_contents,
        ))
        .unwrap();

    messages = consumer.poll().unwrap();
    let mut messages_iter = messages.iter();
    let message_set = messages_iter.next().unwrap();

    assert_eq!(
        1,
        message_set.messages().len(),
        "should only be one message"
    );

    let message_content = message_set.messages()[0].value;
    assert_eq!(
        correct_message_contents, message_content,
        "incorrect message contents"
    );
}