code: public GooglePlus addOAutToken(String oAuthAccessToken, String oAuthRefreshToken, String name, long expires) {
          if (oAuthAccessToken == null || oAuthAccessToken.isEmpty() ||
                  oAuthRefreshToken == null || oAuthRefreshToken.isEmpty()) {
              throw new IllegalArgumentException("A valid OAuth and refresh token is required");
          }
          AuthParams parameterSet = newAuthParams(name, expires);
          parameterSet.set("value", oAuthAccessToken);
          parameterSet.set("refresh_token", oAuthRefreshToken);
          return this;
      }
docs: /*
  Adds an OAuth token to the managed source
  
  @param oAuthAccessToken  an oauth2 token
  @param oAuthRefreshToken an oauth2 refresh token
  @param name              a human friendly name for this auth token
  @param expires           identity resource expiry date/time as a UTC timestamp, i.e. when the token expires
  @return this