code: public HttpServerBuilder contentFrom(String contextRoot, String contentResource){
          URL resource = resolver.resolve(contentResource,CallStack.getCallerClass());
          resources.put(contextRoot, resource);
          return this;
      }
docs: Defines a ZIP resource on the classpath that provides the static content the server should host.
  @param contextRoot
  the root path to the content
  @param contentResource
  the name of the classpath resource denoting a file that should be hosted. If the file denotes a zip file, its
  content is hosted instead of the file itself.
  The path may be absolute or relative to the caller of the method.
  @return
  this builder