def nullif(value, null_if_expr):
    return _ops.NullIf(value, null_if_expr).to_expr()
Verify a challenging hmac signature against a string / shared-secret
dataset/ETHPy150Open cloudera/ibis/ibis/expr/api.py/nullif--crossover with--dataset/ETHPy150Open saltstack/salt/salt/modules/hashutil.py/hmac_signature