code: protected UndertowServletWebServer getUndertowWebServer(Builder builder,
  			DeploymentManager manager, int port) {
  		return new UndertowServletWebServer(builder, manager, getContextPath(),
  				isUseForwardHeaders(), port >= 0, getCompression(), getServerHeader());
  	}
docs: Factory method called to create the {@link UndertowServletWebServer}. Subclasses
  can override this method to return a different {@link UndertowServletWebServer} or
  apply additional processing to the {@link Builder} and {@link DeploymentManager}
  used to bootstrap Undertow
  @param builder the builder
  @param manager the deployment manager
  @param port the port that Undertow should listen on
  @return a new {@link UndertowServletWebServer} instance