aq.rolling() with a custom function?

[jonathancallahan]

I'm trying to use aq.rolling() and aq.escape() to derive a new nowcast value from existing pm25 data.

    let dt = data
    .select(['datetime', id])
    .rename(aq.names('datetime', 'pm25'))
    .derive({ nowcast: aq.escape(aq.rolling(d => nowcastPM(d.pm25), [-12,0])) });

I've tried it with aq.escape(aq.rolling(... and aq.rolling(aq.escape(... but I only ever see a single value being passed down to nowcastPM() rather than an array of 12 values.

Are there any examples of using aq.rolling() with a custom function?