cannot read property 'nodeValue' of null

[wbgillis]

I had to modify the following in getAccessor to prevent above exception when table cell is empty:

getAccessor: funciton(a) {
...
default:
return function(a) {
if (! b.getCell(a).firstChild) {
return('');
}
return b.getCell(a).firstChild.nodeValue; // <= whhen firstChild = null, above exception thrown
}