async getTextData_(uri, netEngine, retryParams) {
    const type = shaka.net.NetworkingEngine.RequestType.SEGMENT;

    const request = shaka.net.NetworkingEngine.makeRequest([uri], retryParams);
    request.method = 'GET';

    this.cmcdManager_.applyTextData(request);

    const response = await netEngine.request(type, request).promise;

    return response.data;
  }
@param {string} uri
@param {!shaka.net.NetworkingEngine} netEngine
@param {shaka.extern.RetryParameters} retryParams
@return {!Promise<BufferSource>}
@private