Generate ROC curve in BQML

bqml_roc_curve.sql

SELECT
  *
FROM
  ML.ROC_CURVE(MODEL `bqml_tutorial.sample_model`,
    (
    SELECT
      IF(totals.transactions IS NULL, 0, 1) AS label,
      IFNULL(device.operatingSystem, "") AS os,
      device.isMobile AS is_mobile,
      IFNULL(geoNetwork.country, "") AS country,
      IFNULL(totals.pageviews, 0) AS pageviews
    FROM
      `bigquery-public-data.google_analytics_sample.ga_sessions_*`
    WHERE
      _TABLE_SUFFIX BETWEEN '20170801' AND '20170830'),
    GENERATE_ARRAY(0.4,0.6,0.01))