def fit(self, dataset):
        """Fit the preprocessor with the dataset.

        # Arguments
            dataset: an instance of `tf.data.Dataset`.
        """
        # TODO: may need to change to a streaming way of fit to reduce the
        # number of iterations through the dataset for speed. Need to be
        # decided when we have more use cases for this fit.
        pass
Fit the preprocessor with the dataset.

        # Arguments
            dataset: an instance of `tf.data.Dataset`.
        
autokeras/engine/preprocessor.py