wunderground api data in processing

wunderground.pde

import com.francisli.processing.http.*;

HttpClient client;

void setup() {
  client = new HttpClient(this, "api.wunderground.com");
  client.GET("/api/[api_key]/conditions/q/CA/San_Francisco.json");
}

void responseReceived(HttpRequest request, HttpResponse response) {
  //// check for HTTP 200 success code
  if (response.statusCode == 200) {
    println(response.getContentAsString());
    JSONObject results = response.getContentAsJSONObject();
    
    String locationInfo = results.get("current_observation").get("display_location").get("full").stringValue();
    String currentTime = results.get("current_observation").get("observation_time").stringValue();
    float tempF = results.get("current_observation").get("temp_f").floatValue();
    float tempC = results.get("current_observation").get("temp_c").floatValue();
    String currentConditions = results.get("current_observation").get("weather").stringValue();
    
    println(locationInfo);
    println(currentTime);
    println("Current conditions: " + currentConditions);
    println("Temperature: " + tempF + "° F / " + tempC + "° C");

  }
}

void draw () {
}

Console output:

San Francisco, CA
Last Updated on December 3, 2:33 PM PST
Current conditions: Partly Cloudy
Temperature: 66.9° F / 19.4° C

I am getting an error
"The type JSONObject is ambiguous"
Can you tell me what might that mean