*
   * https://console.developers.google.com/project
   */
  public static final String GOOGLE_API_KEY = "AIzaSyAx2WZYe0My0i-uGurpvraYJxO7XNbwiGs";
  public static final MediaType MEDIA_TYPE_JSON = MediaType.get("application/json");

  private final OkHttpClient client = new OkHttpClient.Builder()
      .addInterceptor(new GzipRequestInterceptor())
      .build();
  private final Moshi moshi = new Moshi.Builder().build();

  private static final String ENDPOINT = "https://api.github.com/repos/square/okhttp/contributors";
  private static final Moshi MOSHI = new Moshi.Builder().build();
  private static final JsonAdapter<List<Contributor>> CONTRIBUTORS_JSON_ADAPTER = MOSHI.adapter(
      Types.newParameterizedType(List.class, Contributor.class));

  static class Contributor {
    String login;
    int contributions;
  }

        .url("https://api.github.com/repos/square/okhttp/issues")
        .header("User-Agent", "OkHttp Headers.java")
        .addHeader("Accept", "application/json; q=0.5")
        .addHeader("Accept", "application/vnd.github.v3+json")
        .build();

    try (Response response = client.newCall(request).execute()) {
      if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);

import okhttp3.RequestBody;
import okhttp3.Response;

public class PostExample {
  public static final MediaType JSON = MediaType.get("application/json; charset=utf-8");

  final OkHttpClient client = new OkHttpClient();

  String post(String url, String json) throws IOException {
    RequestBody body = RequestBody.create(json, JSON);
    Request request = new Request.Builder()
        .url(url)
        .post(body)
        .build();