Check how missing values are handled

[kMutagene]

example:

we need some way of grouping the flat token list to column-based objects, e.g. persons.

First idea would be using cell address information.

[kMutagene]

CellCollections are sparse, but this is not a problem since we know the adress of any existing values, which means we can check if required values from the same column are present or not.