/// <summary>
 /// Normalize (rescale) several columns according to the specified <paramref name="mode"/>.
 /// </summary>
 /// <param name="catalog">The transform catalog</param>
 /// <param name="mode">The normalization mode (<see cref="Normalizer.NormalizerMode"/>). </param>
 /// <param name="columns">The pairs of input and output columns.</param>
 public static Normalizer Normalizer(this TransformsCatalog catalog, Normalizer.NormalizerMode mode, params (string input, string output)[] columns)
 /// <summary>
 /// Normalize (rescale) the column according to the specified <paramref name="mode"/>.
 /// </summary>
 /// <param name="catalog">The transform catalog</param>
 /// <param name="columnName">The column name</param>
 /// <param name="mode">The normalization mode (<see cref="Normalizer.NormalizerMode"/>). </param>
 public static Normalizer Normalizer(this TransformsCatalog catalog, string columnName, Normalizer.NormalizerMode mode = Runtime.Data.Normalizer.NormalizerMode.MinMax)
 => new Normalizer(CatalogUtils.GetEnvironment(catalog), columnName, mode);