Since version 0.16.5, th following code returns a null worksheet:
XLSX.utils.json_to_sheet([], {header: columns})

Is it now working as it is wanted? If so, how could we create an empty worksheet? In my case it is expected that sometimes the data is an empty array. And an empty worksheet only with headers is expected.

Is your feature request related to a problem or area of OpenRefine? Please describe.

When previewing an importer's results, there is a text field to enter the project name. When pressing Enter in this field, I would expect the project to be created (without having to click the "Create Project" button).

![image](https://user-images.githubusercontent.com/309908/91545213-1a244a80-e921-11ea-

https://www.audiomack.com/data-api/docs

See starter code in #681

This feature would be needed for at minimum the CelebA dataset.

Nested structures could be stored on disk and documented in schema in a "flat" way, but have nesting in as_dataset and in the FeatureDict (for data gen). Whenever applicable, nesting / un-nesting should be consistent with [`tf.contrib.framework.nest.