code: public static Wootric init(Activity activity, String clientId, String accountToken) {
          Wootric local = singleton;
          if(local == null) {
              synchronized (Wootric.class) {
                  local = singleton;
                  if (local == null) {
                      checkNotNull(activity, "Activity");
                      checkNotNull(clientId, "Client Id");
                      checkNotNull(accountToken, "Account Token");
                      singleton = local = new Wootric(activity, clientId, accountToken);
                  }
              }
          }
  
          return local;
      }
docs: It configures the SDK with required parameters.
  
  @param activity Activity where the survey will be presented.
  @param clientId Found in API section of the Wootric's admin panel.
  @param accountToken Found in Install section of the Wootric's admin panel.