def METHOD_NAME(self, y, X=None, **kwargs):  # TODO: remove kwargs later
    """Fit the transformer
    Parameters
    ----------
    y : array-like or None, shape=(n_samples,)
        The endogenous (time-series) array.
    X : array-like, shape=(n_samples, n_features)
        The exogenous array of additional covariates. Must include the
        ``column_name`` feature, which must be a pd.Timestamp dtype.
    """
    y, X = self._check_y_X(y, X, null_allowed=False)
    # enforce pd.DataFrame
    self._check_X(X)
    # we don't _technically_ need to do this, but it seems like a nice bit
    # of friendly validation to make sure that at least _something_ will
    # happen in this transformer.
    if not (self.with_day_of_month or self.with_day_of_week):
        warnings.warn("DateTransformer will have no effect given disabled "
                      "parameters")
    return self