def delete(self, doc):
        if doc.id is None:
            raise DatabaseException('Document does not have id')
        if doc.sid is None:
            try:
                rs = self.db.docs.remove({'id': doc.id}, safe=True)
                assert rs['n'] == 1
            except Exception as e:
                raise DatabaseException(e)
            return None
        doc.data = None
        return self.update(doc)
def test_ccode_boolean():
    assert ccode(x & y) == "x && y"
    assert ccode(x | y) == "x || y"
    assert ccode(~x) == "!x"
    assert ccode(x & y & z) == "x && y && z"
    assert ccode(x | y | z) == "x || y || z"
    assert ccode((x & y) | z) == "z || x && y"
    assert ccode((x | y) & z) == "z && (x || y)"