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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def fit(self, X, y=None, **fit_params):
 """ This method performs preliminary computations in order to set up the figure or perform other analyses. It can also call drawing methods in order to set up various non-instance related figure elements. This method must return self. """


        # Handle the feature names if they're None.
        if self.features_ is None:

            # If X is a data frame, get the columns off it.
            if is_dataframe(X):
                self.features_ = np.array(X.columns)

            # Otherwise create numeric labels for each column.
            else:
                _, ncols = X.shape
                self.features_ = np.arange(0, ncols)

        return self