frozen index breaks table widget

[scottdraves]

Run the following Python3 code:

from beakerx import *
z = TableDisplay([])
z.model = {'alignmentForColumn': {},
 'alignmentForType': {},
 'cellHighlighters': [],
 'columnNames': ['time'],
 'columnOrder': [],
 'columnsFrozen': {"time":True},
 'columnsFrozenRight': {},
 'columnsVisible': {},
 'contextMenuItems': [],
 'contextMenuTags': {},
 'fontColor': [],
 'hasDoubleClickAction': False,
 'hasIndex': 'true',
 'headersVertical': False,
 'rendererForColumn': {},
 'rendererForType': {},
 'stringFormatForColumn': {},
 'stringFormatForType': {},
 'subtype': 'Dictionary',
 'tooManyRows': False,
 'tooltips': [],
 'type': 'TableDisplay',
 'timeZone': 'UTC',
 'types': ['datetime'],
 'values': [['1420174800.0']]}
z

get the following JS stack trace:

selectors.ts:128 Uncaught (in promise) TypeError: Cannot read property 'index' of undefined
    at selectors.ts:128
    at index.js:76
    at index.js:36
    at index.js:90
    at index.js:36
    at ColumnPosition.getColumnByPosition (ColumnPosition.ts:72)
    at DataGridResize.setInitialSectionWidth (DataGridResize.ts:89)
    at DataGridResize.setInitialSectionWidths (DataGridResize.ts:84)
    at DataGridResize.setInitialSize (DataGridResize.ts:49)
    at BeakerxDataGrid.init (BeakerxDataGrid.ts:121)

the issue seems to be 'columnsFrozen': {"time":True}, which is redundant because it's the index, but should not break it. The old tables handle it.