Http Adapter - Make HttpRequestHandlingEndpointSupport public

In working on the AsyncHttp Adapter, I would like to extend the existing Http Adapter. More specifically, I would like to extend org.springframework.integration.http.inbound.HttpRequestHandlingMessagingGateway.

However, several methods within that class have restricted visiblity. Would it be possible to make the following 3 changes?

in "org.springframework.integration.http.inbound.HttpRequestHandlingMessagingGateway"

change:
"private void writeResponse(Object content, ServletServerHttpResponse response, List<MediaType> acceptTypes) throws IOException

{...}"

to
"protected void writeResponse(Object content, ServletServerHttpResponse response, List<MediaType> acceptTypes) throws IOException {...}

"

change:
"private Object handleExceptionInternal(Exception e) throws IOException

{...}"

to:
"protected Object handleExceptionInternal(Exception e) throws IOException {...}

"

change:
"public final void handleRequest(HttpServletRequest servletRequest, HttpServletResponse servletResponse)

{...}

"

to:
"public void handleRequest(HttpServletRequest servletRequest, HttpServletResponse servletResponse) {}"