+Negotiated content types can be extended by overriding:
+- `parseBody(contentType, ctx)` for incoming types.
+- `renderError(contentType, err)` for outgoing types.
+
+Some handler functions are provided:
+- `handlerGetStaticFile(req, res, ctx, file)` will return a file from a configured directory, and also supports including CERN-style header metadata. It will also serve pre-encoded variations (e.g `.gz` or `.br`) if available and requested.
+- `handlerRedirect(req, res, ctx, newPath, statusCode)` will return a redirect response.