+To iterate on a unit test, run the `watch` command above and open
+
+ auto_tests/runner.html
+
+in your browser. You can use the Mocha UI to run just a single test or suite.
+Or you can change `it` to `it.only` to do run just one test in code.
+
+To run a single test from the command line, you can use:
+
+ npm run test -- --grep highlight-series-background
+
+(Note the extra `--`.)