Calling .empty() function when defining selection parameters returns Error: Unrecognized signal name

[krispybird]

Hello,

I get an error when I try to call the .empty() method while defining selection parameters

For example, if I try and call:

const highlight = vl.selectPoint().empty(false); 

I get an error that is returned as Error:: Unrecognized signal name

This occurs for selectPoint, selectInterval, selectSingle, and selectMulti

[domoritz]

Is this a Vega-Lite API issue?

[chatchavan]

The object returned by empty() function has a different prototype than those returned by selectPoint(), or on(). Notebook. Perhaps there's some error in how the empty() is specified for the API generation?