function makeTextStream(language, primary = false) {
    const streamGenerator = new shaka.test.ManifestGenerator.Stream(
        /* manifest= */ null,
        /* isPartial= */ false,
        /* id= */ nextId++,
        /* type= */ shaka.util.ManifestParserUtils.ContentType.TEXT,
        language);
    streamGenerator.primary = primary;
    streamGenerator.originalId = primary ?
      streamGenerator.language + '*' : streamGenerator.language;
    return streamGenerator.build_();
  }
@param {string} language
@param {boolean=} primary
@return {shaka.extern.Stream}
@suppress {accessControls}