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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 new_file(self):
 """ Creates a new editor file. :return: File name. :rtype: unicode """


        file = self.get_untitled_file_name()
        LOGGER.debug("> Creating '{0}' file.".format(file))
        self.set_file(file, is_modified=False, is_untitled=True)
        self.__set_document_signals()
        return file