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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 _ipv4_text_to_int(self, ip_text):
 """convert ip v4 string to integer."""

        if ip_text is None:
            return None
        assert isinstance(ip_text, str)
        return struct.unpack('!I', addrconv.ipv4.text_to_bin(ip_text))[0]