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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 readProtocolVersion(self, data):
 """ Read protocol version @param data: Stream may contain protocol version string (ProtocolVersion) """

        data.readType(self._version)
        if not self._version.value in [ProtocolVersion.RFB003003, ProtocolVersion.RFB003007, ProtocolVersion.RFB003008]:
            self._version.value = ProtocolVersion.UNKNOWN