DecodeFailureHandler

Given the context in which a decode failure occurred (the request, the input and the failure), returns an optional response to the request. None indicates that no action should be taken, and the request might be passed for decoding to other endpoints.

Inputs are decoded in the following order: path, method, query, headers, body. Hence, if there's a decode failure on a query parameter, any method & path inputs of the input must have matched and must have been decoded successfully.