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: winequality_multi.rs
    path of file: ./repos/linfa/algorithms/linfa-logistic/examples
    
    the code of the file until where you have to start completion: use linfa::prelude::*;
use linfa_logistic::MultiLogisticRegression;

use std::error::Error;

fn main() -> Result<(), Box<dyn Error>> {
    let (train, valid) = linfa_datasets::winequality().split_with_ratio(0.9);

    println!(
        "Fit Multinomi
    
fn main() -> Result<(), Box<dyn Error>> {
    let (train, valid) = linfa_datasets::winequality().split_with_ratio(0.9);

    println!(
        "Fit Multinomial Logistic Regression classifier with #{} training points",
        train.nsamples()
    );

    // fit a Logistic regression model with 150 max iterations
    let model = MultiLogisticRegression::default()
        .max_iterations(50)
        .fit(&train)
        .unwrap();

    // predict and map targets
    let pred = model.predict(&valid);

    // create a confusion matrix
    let cm = pred.confusion_matrix(&valid).unwrap();

    // Print the confusion matrix, this will print a table with four entries. On the diagonal are
    // the number of true-positive and true-negative predictions, off the diagonal are
    // false-positive and false-negative
    println!("{:?}", cm);

    // Calculate the accuracy and Matthew Correlation Coefficient (cross-correlation between
    // predicted and targets)
    println!("accuracy {}, MCC {}", cm.accuracy(), cm.mcc());

    Ok(())
}