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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 file_save(self, name, filename=None, folder="", keep_ext=True) -> bool:
 """ Easy save of a file """

        if name in self.files:
            file_object = self.files[name]
            clean_filename = secure_filename(file_object.filename)
            if filename is not None and keep_ext:
                clean_filename = filename + ".%s" % \
                    (clean_filename.rsplit('.', 1)[1].lower())
            elif filename is not None and not keep_ext:
                clean_filename = filename
            file_object.save(os.path.join(
                current_app.config['UPLOADS']['FOLDER'],
                folder, clean_filename))
        return None