customize

Registers handler, run on every problem this catalog produces right before it is sent.

Unlike map, onUnmapped and forStatusCode, this does not decide which problem is built — it adjusts the one already chosen, the same way regardless of which of those three paths chose it. Use it for enrichment that belongs on every document rather than one problem type at a time: a trace id read off the ApplicationCall, for example.

Additive, unlike onUnmapped: each call adds a step, and steps run in registration order, each one seeing what the previous returned. Two unrelated concerns — a trace id and a redaction pass, say — are registered separately without either dropping the other.

Throws