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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 set(self, key, value):
 """ Saves the input with the given key in the section that was passed to the constructor. If either the section or the key are not found, they are created. Does nothing if the given value is None. :type key: str :param key: The key for which to define a value. :type value: str|None :param value: The value that is defined, or None. :rtype: str|None :return: The given value. """

        if value is None:
            return None

        self.parser.set(self.section, key, value)

        # Unfortunately ConfigParser attempts to write a string to the file
        # object, and NamedTemporaryFile uses binary mode. So we nee to create
        # the tempfile, and then re-open it.
        with NamedTemporaryFile(delete=False) as tmpfile:
            pass
        with codecs.open(tmpfile.name, 'w', encoding='utf8') as fp:
            self.parser.write(fp)

        self.file.close()
        shutil.move(tmpfile.name, self.file.name)
        self.file = open(self.file.name)
        return value