I know its possible to add a padding to a sprite legend. But it is (from my knowledge) only possible to add a general padding for all 4 sides.
If i want to add a padding for all 4 sides as a string for example (padding: "0px 5px 0px 5px" or padding: "0 5 0 5") its not working (Maximum call stack size exceeded).

How is it possible to only add a padding to left and right side of the items, but let top and bottom stay at 0? (cause i need the space at top and bottom)

I tried to override the "Ext.chat.legend.SpriteLegend" but i don't really know how to start there.

This is my current legend:
legend: {
type: 'sprite',
docked: 'bottom',

Example: https://fiddle.sencha.com/#view/editor&fiddle/2mtd