Author: David Santos <dawuid(a)gmail.com>
Date: 2020-04-24 (Fri, 24 Apr 2020)
[RESTEASY-2495] HeaderParam could have a ParamConverter related (#2292)
AbstractInvocationCollectionProcessor is processing Array and Collection of elements being
ParamConverter aware. But with single values is delegating in final class to process the
value. HeaderParamProcessor is not being aware of such transformation.