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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 _validate_signal(self, sig):
 """Internal helper to validate a signal. Raise ValueError if the signal number is invalid or uncatchable. Raise RuntimeError if there is a problem setting up the handler. """

        if not isinstance(sig, int):
            raise TypeError('sig must be an int, not {!r}'.format(sig))
        if signal is None:
            raise RuntimeError('Signals are not supported')
        if not (1 <= sig < signal.NSIG):
            raise ValueError('sig {} out of range(1, {})'.format(sig, signal.NSIG))
        if sys.platform == 'win32':
            raise RuntimeError('Signals are not really supported on Windows')