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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 crc(self):
 """ A zlib.crc32 or zlib.adler32 checksum of the current data. Returns crc: int, checksum from zlib.crc32 or zlib.adler32 """

        if self._modified_c or not hasattr(self, '_hashed_crc'):
            if self.flags['C_CONTIGUOUS']:
                self._hashed_crc = crc32(self)
            else:
                # the case where we have sliced our nice
                # contiguous array into a non- contiguous block
                # for example (note slice *after* track operation):
                # t = util.tracked_array(np.random.random(10))[::-1]
                contiguous = np.ascontiguousarray(self)
                self._hashed_crc = crc32(contiguous)
        self._modified_c = False
        return self._hashed_crc