code: public void dispose() {
          logDebug("Disposing.");
          mSetupDone = false;
          if (mServiceConn != null) {
              logDebug("Unbinding from service.");
              if (mContext != null) mContext.unbindService(mServiceConn);
          }
          mDisposed = true;
          mContext = null;
          mServiceConn = null;
          mService = null;
          mPurchaseListener = null;
      }
docs: Dispose of object, releasing resources. It's very important to call this
  method when you are done with this object. It will release any resources
  used by it such as service connections. Naturally, once the object is
  disposed of, it can't be used again.