public VKParameters getPreparedParameters() {
    if (mPreparedParameters == null) {
      mPreparedParameters = new VKParameters(mMethodParameters);

      // Set current access token from SDK object
      VKAccessToken token = VKSdk.getAccessToken();
      if (token != null) mPreparedParameters.put(VKApiConst.ACCESS_TOKEN, token.accessToken);
      if (!this.secure)
        if (token != null && (token.secret != null || token.httpsRequired)) {
          this.secure = true;
        }
      // Set actual version of API
      mPreparedParameters.put(VKApiConst.VERSION, VKSdkVersion.API_VERSION);
      // Set preferred language for request
      mPreparedParameters.put(VKApiConst.LANG, getLang());

      if (this.secure) {
        // If request is secure, we need all urls as https
        mPreparedParameters.put(VKApiConst.HTTPS, "1");
      }
      if (token != null && token.secret != null) {
        // If it not, generate signature of request
        String sig = generateSig(token);
        mPreparedParameters.put(VKApiConst.SIG, sig);
      }
      // From that moment you cannot modify parameters.
      // Specially for http loading
    }
    return mPreparedParameters;
  }
 /**
  * Adds additional parameter to that request
  *
  * @param key parameter name
  * @param value parameter value
  */
 public void addExtraParameter(String key, Object value) {
   mMethodParameters.put(key, value);
 }