'Set the response code and response headers on the request object, but
do not flush them.  The caller is responsible for doing a write in
order for anything to actually be written out in response to the
request.
This must be called in the I/O thread.'

def _sendResponseHeaders(self):

    (code, message) = self.status.split(None, 1)
    code = int(code)
    self.request.setResponseCode(code, _wsgiStringToBytes(message))
    for (name, value) in self.headers:
        if (name.lower() not in ('server', 'date')):
            self.request.responseHeaders.addRawHeader(_wsgiStringToBytes(name), _wsgiStringToBytes(value))
