def _add_constants(self, key, val):
        if key in self._int_constants:
            if self._int_constants[key] == val:
                return     # ignore identical double declarations
            raise api.FFIError(
                "multiple declarations of constant: %s" % (key,))
        self._int_constants[key] = val
dataset/ETHPy150Open cloudera/hue/desktop/core/ext-py/cffi-1.5.2/cffi/cparser.py/Parser._add_constants/original