a data fetcher to create toy data on the fly?

[sehilyi]

data: { type: 'simulated' }, // ← refer to the track encoding and generate proper data fields automatically
... // track definition

This can be helpful in several use cases.

• for users to exercise gosling grammar without needing to consider data
• for several tools, like GenoREC and AutoGosling, to recommend Gosling visualization (spec) without including acutal data