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: mean_absolute_error.rs
    path of file: ./repos/smartcore/src/metrics
    
    the code of the file until where you have to start completion: //! # Mean Absolute Error
//!
//! MAE measures the average magnitude of the errors in a set of predictions, without considering their directi
    
    fn mean_absolute_error() {
        let y_true: Vec<f64> = vec![3., -0.5, 2., 7.];
        let y_pred: Vec<f64> = vec![2.5, 0.0, 2., 8.];

        let score1: f64 = MeanAbsoluteError::new().get_score(&y_true, &y_pred);
        let score2: f64 = MeanAbsoluteError::new().get_score(&y_true, &y_true);

        assert!((score1 - 0.5).abs() < 1e-8);
        assert!((score2 - 0.0).abs() < 1e-8);
    }