How to use the @tensorflow/tfjs-data.csv function in @tensorflow/tfjs-data

private async prepareDataset(url: string) {
    // We want to predict the column "medv", which represents a median value of
    // a home (in $1000s), so we mark it as a label.
    const csvDataset = tfd.csv(url, {columnConfigs: {medv: {isLabel: true}}});

    // Reduces the object-type data to an array of numbers.
    const convertedDataset =
        csvDataset.map((row: Array<{[key: string]: number}>) => {
          const [rawFeatures, rawLabel] = row;
          const convertedFeatures = Object.values(rawFeatures);
          const convertedLabel = [rawLabel['medv']];
          return [convertedFeatures, convertedLabel];
        });
    return {
      dataset: convertedDataset.shuffle(100),
      numFeatures: (await csvDataset.columnNames()).length - 1
    };
  }
}