One way of doing this would be to:

1. Update ClickThroughRateInstrument to work with instances of Instrument, e.g.

const i = mw.eventLog.newInstrument( STREAM_NAME, SCHEMA_ID );

ClickThroughRateInstrument.start( ELEMENT_SELECTOR, ELEMENT_FRIENDLY_NAME, instrument );

2. Update the toy experiment code to use Instrument and the new API above

Change #1115130 had a related patch set uploaded (by Clare Ming; author: Clare Ming):

[mediawiki/extensions/WikimediaEvents@master] Make CTR instrument pass in experiment name

https://gerrit.wikimedia.org/r/1115130

Change #1115130 merged by jenkins-bot:

[mediawiki/extensions/WikimediaEvents@master] Make CTR instrument pass in experiment name

https://gerrit.wikimedia.org/r/1115130

Change #1122232 had a related patch set uploaded (by Clare Ming; author: Clare Ming):

[mediawiki/extensions/WikimediaEvents@wmf/1.44.0-wmf.17] Make CTR instrument pass in experiment name

https://gerrit.wikimedia.org/r/1122232

Change #1122232 merged by jenkins-bot:

[mediawiki/extensions/WikimediaEvents@wmf/1.44.0-wmf.17] Make CTR instrument pass in experiment name

https://gerrit.wikimedia.org/r/1122232

Mentioned in SAL (#wikimedia-operations) [2025-02-24T22:42:51Z] <cjming@deploy2002> Started scap sync-world: Backport for [[gerrit:1122232|Make CTR instrument pass in experiment name (T384911)]]

Mentioned in SAL (#wikimedia-operations) [2025-02-24T22:45:26Z] <cjming@deploy2002> cjming: Backport for [[gerrit:1122232|Make CTR instrument pass in experiment name (T384911)]] synced to the testservers (https://wikitech.wikimedia.org/wiki/Mwdebug)

Mentioned in SAL (#wikimedia-operations) [2025-02-24T22:52:09Z] <cjming@deploy2002> Finished scap sync-world: Backport for [[gerrit:1122232|Make CTR instrument pass in experiment name (T384911)]] (duration: 09m 17s)