@abstractmethod
def fit(self, X, y=None):
    'Placeholder for fit. Subclasses should implement this method!\n\n        Fit the model with X.\n\n        Parameters\n        ----------\n        X : array-like of shape (n_samples, n_features)\n            Training data, where `n_samples` is the number of samples and\n            `n_features` is the number of features.\n\n        Returns\n        -------\n        self : object\n            Returns the instance itself.\n        '
Placeholder for fit. Subclasses should implement this method!

Fit the model with X.

Parameters
----------
X : array-like of shape (n_samples, n_features)
    Training data, where `n_samples` is the number of samples and
    `n_features` is the number of features.

Returns
-------
self : object
    Returns the instance itself.
@abstractmethod
def fit(self, X, y=None):
    'Placeholder for fit. Subclasses should implement this method!\n\n        Fit the model with X.\n\n        Parameters\n        ----------\n        X : array-like of shape (n_samples, n_features)\n            Training data, where `n_samples` is the number of samples and\n            `n_features` is the number of features.\n\n        Returns\n        -------\n        self : object\n            Returns the instance itself.\n        '