getRequestFromFastify = (shim, fn, fnName, args) => {
  const [request] = args

  // request is Fastify request
  // object, get IncomingMessage from .raw
  if (request && request.raw) {
    return request.raw
  }

  return request
}
Retrieves the IncomingMessage from a Fastify request.  Depending on the
context of this function it either exists on `request.raw` or just `request`

@param {WebFrameworkShim} shim
@param {Function} fn middleware function executing
@param {string} fnName name of middleware executing
@param {args} args that are passed to middleware
@returns {IncomingMessage}