code: @Override public RackResponse call(RackEnvironment environment) {
      RubyHash environmentHash = convertToRubyHash(environment.entrySet());
  
      RubyArray response = callRackApplication(environmentHash);
  
      return convertToJavaRackResponse(response);
    }
docs: Calls the delegate Rack application, translating into and back out of the JRuby interpreter.
  
  @param environment the Rack environment
  @return the Rack response