createData_() {
    if (!this.config_.sessionId) {
      this.config_.sessionId = window.crypto.randomUUID();
    }
    return {
      v: this.config_.version,
      sf: this.sf_,
      sid: this.config_.sessionId,
      cid: this.config_.contentId,
      mtp: this.playerInterface_.getBandwidthEstimate() / 1000,
    };
  }
Create baseline CMCD data

@return {CmcdData}
@private