diff --git a/src/algorithm/neighbour/cover_tree.rs b/src/algorithm/neighbour/cover_tree.rs
index 553dc99..96a3389 100644
--- a/src/algorithm/neighbour/cover_tree.rs
+++ b/src/algorithm/neighbour/cover_tree.rs
@@ -24,7 +24,8 @@
 //! ```
 use std::fmt::Debug;
 
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 use crate::algorithm::sort::heap_select::HeapSelection;
 use crate::error::{Failed, FailedError};
diff --git a/src/algorithm/neighbour/linear_search.rs b/src/algorithm/neighbour/linear_search.rs
index d82e575..f89e751 100644
--- a/src/algorithm/neighbour/linear_search.rs
+++ b/src/algorithm/neighbour/linear_search.rs
@@ -22,7 +22,8 @@
 //!
 //! ```
 
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 use std::cmp::{Ordering, PartialOrd};
 use std::marker::PhantomData;
 
diff --git a/src/algorithm/neighbour/mod.rs b/src/algorithm/neighbour/mod.rs
index 9e432bd..321ec01 100644
--- a/src/algorithm/neighbour/mod.rs
+++ b/src/algorithm/neighbour/mod.rs
@@ -35,7 +35,8 @@ use crate::algorithm::neighbour::linear_search::LinearKNNSearch;
 use crate::error::Failed;
 use crate::math::distance::Distance;
 use crate::math::num::RealNumber;
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 pub(crate) mod bbd_tree;
 /// tree data structure for fast nearest neighbor search
diff --git a/src/cluster/dbscan.rs b/src/cluster/dbscan.rs
index a117982..73d686d 100644
--- a/src/cluster/dbscan.rs
+++ b/src/cluster/dbscan.rs
@@ -43,7 +43,8 @@
 use std::fmt::Debug;
 use std::iter::Sum;
 
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 use crate::algorithm::neighbour::{KNNAlgorithm, KNNAlgorithmName};
 use crate::api::{Predictor, UnsupervisedEstimator};
diff --git a/src/cluster/kmeans.rs b/src/cluster/kmeans.rs
index 78c9105..a454b1f 100644
--- a/src/cluster/kmeans.rs
+++ b/src/cluster/kmeans.rs
@@ -56,7 +56,8 @@ use rand::Rng;
 use std::fmt::Debug;
 use std::iter::Sum;
 
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 use crate::algorithm::neighbour::bbd_tree::BBDTree;
 use crate::api::{Predictor, UnsupervisedEstimator};
diff --git a/src/decomposition/pca.rs b/src/decomposition/pca.rs
index 626f268..e3212e3 100644
--- a/src/decomposition/pca.rs
+++ b/src/decomposition/pca.rs
@@ -47,7 +47,8 @@
 //! <script id="MathJax-script" async src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js"></script>
 use std::fmt::Debug;
 
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 use crate::api::{Transformer, UnsupervisedEstimator};
 use crate::error::Failed;
diff --git a/src/decomposition/svd.rs b/src/decomposition/svd.rs
index 7dc48dc..5524e29 100644
--- a/src/decomposition/svd.rs
+++ b/src/decomposition/svd.rs
@@ -46,7 +46,8 @@
 use std::fmt::Debug;
 use std::marker::PhantomData;
 
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 use crate::api::{Transformer, UnsupervisedEstimator};
 use crate::error::Failed;
diff --git a/src/ensemble/random_forest_classifier.rs b/src/ensemble/random_forest_classifier.rs
index 74f210c..62e83b5 100644
--- a/src/ensemble/random_forest_classifier.rs
+++ b/src/ensemble/random_forest_classifier.rs
@@ -49,7 +49,8 @@ use std::default::Default;
 use std::fmt::Debug;
 
 use rand::Rng;
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 use crate::api::{Predictor, SupervisedEstimator};
 use crate::error::Failed;
diff --git a/src/ensemble/random_forest_regressor.rs b/src/ensemble/random_forest_regressor.rs
index 74a1b59..18c2f69 100644
--- a/src/ensemble/random_forest_regressor.rs
+++ b/src/ensemble/random_forest_regressor.rs
@@ -47,7 +47,8 @@ use std::default::Default;
 use std::fmt::Debug;
 
 use rand::Rng;
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 use crate::api::{Predictor, SupervisedEstimator};
 use crate::error::Failed;
diff --git a/src/error/mod.rs b/src/error/mod.rs
index 9a9bb8b..4e84f6e 100644
--- a/src/error/mod.rs
+++ b/src/error/mod.rs
@@ -2,7 +2,8 @@
 use std::error::Error;
 use std::fmt;
 
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 /// Generic error to be raised when something goes wrong.
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
diff --git a/src/linalg/naive/dense_matrix.rs b/src/linalg/naive/dense_matrix.rs
index 9816a28..1a9b3a6 100644
--- a/src/linalg/naive/dense_matrix.rs
+++ b/src/linalg/naive/dense_matrix.rs
@@ -1,7 +1,8 @@
 #![allow(clippy::ptr_arg)]
 use std::fmt;
 use std::fmt::Debug;
-#[cfg(feature = "serde")] use std::marker::PhantomData;
+#[cfg(feature = "serde")]
+use std::marker::PhantomData;
 use std::ops::Range;
 
 #[cfg(feature = "serde")]
diff --git a/src/linear/elastic_net.rs b/src/linear/elastic_net.rs
index 7e7a29a..f4a4326 100644
--- a/src/linear/elastic_net.rs
+++ b/src/linear/elastic_net.rs
@@ -56,7 +56,8 @@
 //! <script id="MathJax-script" async src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js"></script>
 use std::fmt::Debug;
 
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 use crate::api::{Predictor, SupervisedEstimator};
 use crate::error::Failed;
diff --git a/src/linear/lasso.rs b/src/linear/lasso.rs
index 8f46bbc..17712b1 100644
--- a/src/linear/lasso.rs
+++ b/src/linear/lasso.rs
@@ -24,7 +24,8 @@
 //! <script id="MathJax-script" async src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js"></script>
 use std::fmt::Debug;
 
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 use crate::api::{Predictor, SupervisedEstimator};
 use crate::error::Failed;
diff --git a/src/linear/linear_regression.rs b/src/linear/linear_regression.rs
index 6d24312..290a2db 100644
--- a/src/linear/linear_regression.rs
+++ b/src/linear/linear_regression.rs
@@ -62,7 +62,8 @@
 //! <script id="MathJax-script" async src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js"></script>
 use std::fmt::Debug;
 
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 use crate::api::{Predictor, SupervisedEstimator};
 use crate::error::Failed;
diff --git a/src/linear/logistic_regression.rs b/src/linear/logistic_regression.rs
index cdf78d1..45777be 100644
--- a/src/linear/logistic_regression.rs
+++ b/src/linear/logistic_regression.rs
@@ -56,7 +56,8 @@ use std::cmp::Ordering;
 use std::fmt::Debug;
 use std::marker::PhantomData;
 
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 use crate::api::{Predictor, SupervisedEstimator};
 use crate::error::Failed;
diff --git a/src/linear/ridge_regression.rs b/src/linear/ridge_regression.rs
index 5afa2f9..4e1ebad 100644
--- a/src/linear/ridge_regression.rs
+++ b/src/linear/ridge_regression.rs
@@ -58,7 +58,8 @@
 //! <script id="MathJax-script" async src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js"></script>
 use std::fmt::Debug;
 
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 use crate::api::{Predictor, SupervisedEstimator};
 use crate::error::Failed;
diff --git a/src/math/distance/euclidian.rs b/src/math/distance/euclidian.rs
index 6385f6e..b06d7d1 100644
--- a/src/math/distance/euclidian.rs
+++ b/src/math/distance/euclidian.rs
@@ -18,7 +18,8 @@
 //!
 //! <script src="https://polyfill.io/v3/polyfill.min.js?features=es6"></script>
 //! <script id="MathJax-script" async src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js"></script>
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 use crate::math::num::RealNumber;
 
diff --git a/src/math/distance/hamming.rs b/src/math/distance/hamming.rs
index bdd8e14..d23b57f 100644
--- a/src/math/distance/hamming.rs
+++ b/src/math/distance/hamming.rs
@@ -19,7 +19,8 @@
 //! <script src="https://polyfill.io/v3/polyfill.min.js?features=es6"></script>
 //! <script id="MathJax-script" async src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js"></script>
 
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 use crate::math::num::RealNumber;
 
diff --git a/src/math/distance/mahalanobis.rs b/src/math/distance/mahalanobis.rs
index 9f47894..7ff86e9 100644
--- a/src/math/distance/mahalanobis.rs
+++ b/src/math/distance/mahalanobis.rs
@@ -44,7 +44,8 @@
 
 use std::marker::PhantomData;
 
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 use crate::math::num::RealNumber;
 
diff --git a/src/math/distance/manhattan.rs b/src/math/distance/manhattan.rs
index 758763b..3162178 100644
--- a/src/math/distance/manhattan.rs
+++ b/src/math/distance/manhattan.rs
@@ -17,7 +17,8 @@
 //! ```
 //! <script src="https://polyfill.io/v3/polyfill.min.js?features=es6"></script>
 //! <script id="MathJax-script" async src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js"></script>
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 use crate::math::num::RealNumber;
 
diff --git a/src/math/distance/minkowski.rs b/src/math/distance/minkowski.rs
index e953571..1e97ea8 100644
--- a/src/math/distance/minkowski.rs
+++ b/src/math/distance/minkowski.rs
@@ -21,7 +21,8 @@
 //! <script src="https://polyfill.io/v3/polyfill.min.js?features=es6"></script>
 //! <script id="MathJax-script" async src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js"></script>
 
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 use crate::math::num::RealNumber;
 
diff --git a/src/metrics/accuracy.rs b/src/metrics/accuracy.rs
index c5a129b..6912a4c 100644
--- a/src/metrics/accuracy.rs
+++ b/src/metrics/accuracy.rs
@@ -16,7 +16,8 @@
 //!
 //! <script src="https://polyfill.io/v3/polyfill.min.js?features=es6"></script>
 //! <script id="MathJax-script" async src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js"></script>
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 use crate::linalg::BaseVector;
 use crate::math::num::RealNumber;
diff --git a/src/metrics/auc.rs b/src/metrics/auc.rs
index f352ca7..508295b 100644
--- a/src/metrics/auc.rs
+++ b/src/metrics/auc.rs
@@ -20,7 +20,8 @@
 //! * ["The ROC-AUC and the Mann-Whitney U-test", Haupt, J.](https://johaupt.github.io/roc-auc/model%20evaluation/Area_under_ROC_curve.html)
 #![allow(non_snake_case)]
 
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 use crate::algorithm::sort::quick_sort::QuickArgSort;
 use crate::linalg::BaseVector;
diff --git a/src/metrics/cluster_hcv.rs b/src/metrics/cluster_hcv.rs
index 40e5173..d881bdc 100644
--- a/src/metrics/cluster_hcv.rs
+++ b/src/metrics/cluster_hcv.rs
@@ -1,4 +1,5 @@
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 use crate::linalg::BaseVector;
 use crate::math::num::RealNumber;
diff --git a/src/metrics/f1.rs b/src/metrics/f1.rs
index 29f989e..d957d9b 100644
--- a/src/metrics/f1.rs
+++ b/src/metrics/f1.rs
@@ -18,7 +18,8 @@
 //!
 //! <script src="https://polyfill.io/v3/polyfill.min.js?features=es6"></script>
 //! <script id="MathJax-script" async src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js"></script>
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 use crate::linalg::BaseVector;
 use crate::math::num::RealNumber;
diff --git a/src/metrics/mean_absolute_error.rs b/src/metrics/mean_absolute_error.rs
index 1049589..db3039f 100644
--- a/src/metrics/mean_absolute_error.rs
+++ b/src/metrics/mean_absolute_error.rs
@@ -18,7 +18,8 @@
 //!
 //! <script src="https://polyfill.io/v3/polyfill.min.js?features=es6"></script>
 //! <script id="MathJax-script" async src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js"></script>
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 use crate::linalg::BaseVector;
 use crate::math::num::RealNumber;
diff --git a/src/metrics/mean_squared_error.rs b/src/metrics/mean_squared_error.rs
index 3bcb7e1..3003e5d 100644
--- a/src/metrics/mean_squared_error.rs
+++ b/src/metrics/mean_squared_error.rs
@@ -18,7 +18,8 @@
 //!
 //! <script src="https://polyfill.io/v3/polyfill.min.js?features=es6"></script>
 //! <script id="MathJax-script" async src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js"></script>
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 use crate::linalg::BaseVector;
 use crate::math::num::RealNumber;
diff --git a/src/metrics/precision.rs b/src/metrics/precision.rs
index 806c119..2bd0dcf 100644
--- a/src/metrics/precision.rs
+++ b/src/metrics/precision.rs
@@ -18,7 +18,8 @@
 //!
 //! <script src="https://polyfill.io/v3/polyfill.min.js?features=es6"></script>
 //! <script id="MathJax-script" async src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js"></script>
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 use crate::linalg::BaseVector;
 use crate::math::num::RealNumber;
diff --git a/src/metrics/r2.rs b/src/metrics/r2.rs
index 0d661b7..c710ef5 100644
--- a/src/metrics/r2.rs
+++ b/src/metrics/r2.rs
@@ -18,7 +18,8 @@
 //!
 //! <script src="https://polyfill.io/v3/polyfill.min.js?features=es6"></script>
 //! <script id="MathJax-script" async src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js"></script>
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 use crate::linalg::BaseVector;
 use crate::math::num::RealNumber;
diff --git a/src/metrics/recall.rs b/src/metrics/recall.rs
index 22f5402..d1fad56 100644
--- a/src/metrics/recall.rs
+++ b/src/metrics/recall.rs
@@ -18,7 +18,8 @@
 //!
 //! <script src="https://polyfill.io/v3/polyfill.min.js?features=es6"></script>
 //! <script id="MathJax-script" async src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js"></script>
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 use crate::linalg::BaseVector;
 use crate::math::num::RealNumber;
diff --git a/src/naive_bayes/bernoulli.rs b/src/naive_bayes/bernoulli.rs
index 7233b83..cdbfa80 100644
--- a/src/naive_bayes/bernoulli.rs
+++ b/src/naive_bayes/bernoulli.rs
@@ -42,7 +42,8 @@ use crate::math::num::RealNumber;
 use crate::math::vector::RealNumberVector;
 use crate::naive_bayes::{BaseNaiveBayes, NBDistribution};
 
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 /// Naive Bayes classifier for Bearnoulli features
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
diff --git a/src/naive_bayes/categorical.rs b/src/naive_bayes/categorical.rs
index c6b66c6..dc8587a 100644
--- a/src/naive_bayes/categorical.rs
+++ b/src/naive_bayes/categorical.rs
@@ -36,7 +36,8 @@ use crate::linalg::BaseVector;
 use crate::linalg::Matrix;
 use crate::math::num::RealNumber;
 use crate::naive_bayes::{BaseNaiveBayes, NBDistribution};
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 /// Naive Bayes classifier for categorical features
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
diff --git a/src/naive_bayes/gaussian.rs b/src/naive_bayes/gaussian.rs
index 6ba78bb..c27c396 100644
--- a/src/naive_bayes/gaussian.rs
+++ b/src/naive_bayes/gaussian.rs
@@ -30,7 +30,8 @@ use crate::linalg::Matrix;
 use crate::math::num::RealNumber;
 use crate::math::vector::RealNumberVector;
 use crate::naive_bayes::{BaseNaiveBayes, NBDistribution};
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 /// Naive Bayes classifier for categorical features
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
diff --git a/src/naive_bayes/mod.rs b/src/naive_bayes/mod.rs
index 9a24466..f7c8da6 100644
--- a/src/naive_bayes/mod.rs
+++ b/src/naive_bayes/mod.rs
@@ -39,7 +39,8 @@ use crate::error::Failed;
 use crate::linalg::BaseVector;
 use crate::linalg::Matrix;
 use crate::math::num::RealNumber;
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 use std::marker::PhantomData;
 
 /// Distribution used in the Naive Bayes classifier.
diff --git a/src/naive_bayes/multinomial.rs b/src/naive_bayes/multinomial.rs
index 23382a1..fa91020 100644
--- a/src/naive_bayes/multinomial.rs
+++ b/src/naive_bayes/multinomial.rs
@@ -42,7 +42,8 @@ use crate::math::num::RealNumber;
 use crate::math::vector::RealNumberVector;
 use crate::naive_bayes::{BaseNaiveBayes, NBDistribution};
 
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 /// Naive Bayes classifier for Multinomial features
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
diff --git a/src/neighbors/knn_classifier.rs b/src/neighbors/knn_classifier.rs
index 0f75220..839eea3 100644
--- a/src/neighbors/knn_classifier.rs
+++ b/src/neighbors/knn_classifier.rs
@@ -33,7 +33,8 @@
 //!
 use std::marker::PhantomData;
 
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 use crate::algorithm::neighbour::{KNNAlgorithm, KNNAlgorithmName};
 use crate::api::{Predictor, SupervisedEstimator};
diff --git a/src/neighbors/knn_regressor.rs b/src/neighbors/knn_regressor.rs
index 86bfd85..1edf86a 100644
--- a/src/neighbors/knn_regressor.rs
+++ b/src/neighbors/knn_regressor.rs
@@ -36,7 +36,8 @@
 //!
 use std::marker::PhantomData;
 
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 use crate::algorithm::neighbour::{KNNAlgorithm, KNNAlgorithmName};
 use crate::api::{Predictor, SupervisedEstimator};
diff --git a/src/neighbors/mod.rs b/src/neighbors/mod.rs
index 6beb75e..86b1e46 100644
--- a/src/neighbors/mod.rs
+++ b/src/neighbors/mod.rs
@@ -33,7 +33,8 @@
 //! <script id="MathJax-script" async src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js"></script>
 
 use crate::math::num::RealNumber;
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 /// K Nearest Neighbors Classifier
 pub mod knn_classifier;
diff --git a/src/svm/mod.rs b/src/svm/mod.rs
index abe8071..068f773 100644
--- a/src/svm/mod.rs
+++ b/src/svm/mod.rs
@@ -26,7 +26,8 @@
 pub mod svc;
 pub mod svr;
 
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 use crate::linalg::BaseVector;
 use crate::math::num::RealNumber;
diff --git a/src/svm/svc.rs b/src/svm/svc.rs
index 0582cdc..9d77812 100644
--- a/src/svm/svc.rs
+++ b/src/svm/svc.rs
@@ -76,7 +76,8 @@ use std::marker::PhantomData;
 
 use rand::seq::SliceRandom;
 
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 use crate::api::{Predictor, SupervisedEstimator};
 use crate::error::Failed;
@@ -103,10 +104,13 @@ pub struct SVCParameters<T: RealNumber, M: Matrix<T>, K: Kernel<T, M::RowVector>
 
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[derive(Debug)]
-#[cfg_attr(feature = "serde", serde(bound(
-    serialize = "M::RowVector: Serialize, K: Serialize, T: Serialize",
-    deserialize = "M::RowVector: Deserialize<'de>, K: Deserialize<'de>, T: Deserialize<'de>",
-)))]
+#[cfg_attr(
+    feature = "serde",
+    serde(bound(
+        serialize = "M::RowVector: Serialize, K: Serialize, T: Serialize",
+        deserialize = "M::RowVector: Deserialize<'de>, K: Deserialize<'de>, T: Deserialize<'de>",
+    ))
+)]
 /// Support Vector Classifier
 pub struct SVC<T: RealNumber, M: Matrix<T>, K: Kernel<T, M::RowVector>> {
     classes: Vec<T>,
diff --git a/src/svm/svr.rs b/src/svm/svr.rs
index 4d61b97..cbb1ea5 100644
--- a/src/svm/svr.rs
+++ b/src/svm/svr.rs
@@ -68,7 +68,8 @@ use std::cell::{Ref, RefCell};
 use std::fmt::Debug;
 use std::marker::PhantomData;
 
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 use crate::api::{Predictor, SupervisedEstimator};
 use crate::error::Failed;
@@ -95,10 +96,13 @@ pub struct SVRParameters<T: RealNumber, M: Matrix<T>, K: Kernel<T, M::RowVector>
 
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[derive(Debug)]
-#[cfg_attr(feature = "serde", serde(bound(
-    serialize = "M::RowVector: Serialize, K: Serialize, T: Serialize",
-    deserialize = "M::RowVector: Deserialize<'de>, K: Deserialize<'de>, T: Deserialize<'de>",
-)))]
+#[cfg_attr(
+    feature = "serde",
+    serde(bound(
+        serialize = "M::RowVector: Serialize, K: Serialize, T: Serialize",
+        deserialize = "M::RowVector: Deserialize<'de>, K: Deserialize<'de>, T: Deserialize<'de>",
+    ))
+)]
 
 /// Epsilon-Support Vector Regression
 pub struct SVR<T: RealNumber, M: Matrix<T>, K: Kernel<T, M::RowVector>> {
diff --git a/src/tree/decision_tree_classifier.rs b/src/tree/decision_tree_classifier.rs
index b014152..7575a5a 100644
--- a/src/tree/decision_tree_classifier.rs
+++ b/src/tree/decision_tree_classifier.rs
@@ -68,7 +68,8 @@ use std::fmt::Debug;
 use std::marker::PhantomData;
 
 use rand::seq::SliceRandom;
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 use crate::algorithm::sort::quick_sort::QuickArgSort;
 use crate::api::{Predictor, SupervisedEstimator};
diff --git a/src/tree/decision_tree_regressor.rs b/src/tree/decision_tree_regressor.rs
index ef8c52c..d1292db 100644
--- a/src/tree/decision_tree_regressor.rs
+++ b/src/tree/decision_tree_regressor.rs
@@ -63,7 +63,8 @@ use std::default::Default;
 use std::fmt::Debug;
 
 use rand::seq::SliceRandom;
-#[cfg(feature = "serde")] use serde::{Deserialize, Serialize};
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
 
 use crate::algorithm::sort::quick_sort::QuickArgSort;
 use crate::api::{Predictor, SupervisedEstimator};