NO_OP For Files with Multiple Samples

### Context
These are very tricky:

https://www.ebi.ac.uk/arrayexpress/experiments/E-GEOD-19298/?array=A-AFFY-38&page=1&pagesize=250

Multiple samples, each with multiple unlabeled columns. And they're quite rare:

https://www.ebi.ac.uk/arrayexpress/experiments/browse.html?array=A-AFFY-38

Start by inspecting the linked ArrayExpress experiment E-GEOD-19298 and the A-AFFY-38 browse results to understand the multiple-sample, unlabeled-column cases. Trace the existing handling for these files and define the expected no-op behavior before identifying the relevant tests or entry point; done means the cases are handled without producing an incorrect dataset.

Written by the indexing model from the issue text.