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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 extract_message_value(self, name):
        ''' search message to find and extract a named value '''
        name += ":"
        assert(self._message)
        _start = self._message.find(name)
        if _start >= 0:
            _start += len(name) + 1
            _end = self._message.find("\n", _start)
            _value = self._message[_start:_end]
            return _value.strip()

        return None