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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 _setintbe(self, intbe, length=None):
 """Set bitstring to a big-endian signed int interpretation."""

        if length is not None and length % 8 != 0:
            raise CreationError("Big-endian integers must be whole-byte. "
                                "Length = {0} bits.", length)
        self._setint(intbe, length)