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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_transform(self, X, y=None, **params):
 """Learn vocabulary and return document id matrix. This is equivalent to fit followed by transform. Args: X : iterable an iterable which yields either str, unicode or file objects. Returns: list : document id matrix. list: label id matrix. """

        return self.fit(X, y).transform(X, y)