def fit(self, x: np.ndarray, y: np.ndarray, **kwargs) -> None:
        """
        Fit the regressor on the training set `(x, y)`.

        :param x: Training data.
        :param y: Target values.
        :param kwargs: Dictionary of framework-specific arguments. These should be parameters supported by the
               `fit` function in `sklearn` regressor and will be passed to this function as such.
        """
        # Apply preprocessing
        x_preprocessed, y_preprocessed = self._apply_preprocessing(x, y, fit=True)

        self.model.fit(x_preprocessed, y_preprocessed, **kwargs)
        self._input_shape = self._get_input_shape(self.model)

        Fit the regressor on the training set `(x, y)`.

        :param x: Training data.
        :param y: Target values.
        :param kwargs: Dictionary of framework-specific arguments. These should be parameters supported by the
               `fit` function in `sklearn` regressor and will be passed to this function as such.
        
art/estimators/regression/scikitlearn.py