Replacing resource which has no assignments fails

[pmiklashevych]

http://lh/bryntum-suite/schedulerpro/examples/constraints/
In console:

scheduler.eventStore.removeAll()

then

scheduler.resourceStore.data = [{ id : 1, name : 'test' }]

See the error:

HorizontalRendering.js:668 Uncaught TypeError: Cannot read property 'size' of undefined
    at HorizontalRendering.calculateRowHeight (HorizontalRendering.js:668)
    at SchedulerPro.getRowHeight (SchedulerBase.js:668)
    at Row.render (Row.js:539)
    at RowManager.renderFromRow (RowManager.js:938)
    at RowManager.reinitialize (RowManager.js:174)
    at SchedulerPro.renderRows (GridBase.js:2897)
    at functionChainRunner (InstancePlugin.js:359)
    at SchedulerPro.plugInto.<computed> [as renderRows] (InstancePlugin.js:330)
    at SchedulerPro.onStoreDataChange (GridBase.js:1579)
    at ResourceStore.trigger (Events.js:1138)

User has similar problem with undefined "assigned" property.
https://www.bryntum.com/forum/viewtopic.php?p=84722#p84722

Need to check AbstractResourceStoreMixin.ts and AbstractEventStoreMixin.ts in the Engine.

                for (const assignment of existingRecord.assigned) {
                    assignment.resource    = resourceRecord
                }

                    for (const assignment of existingRecord.assigned) {
                        assignment.event = eventRecord
                    }

[matsbryntse]

No repro