columns property
The column tracks, when layout is NodeLayout.table. Each is a size
in the same three-valued vocabulary as a node's: null hugs the
widest cell in the column, a number is fixed, double.infinity takes
what is left. A column nobody declared hugs.
The tracks belong to the TABLE, not to the cells, and that is the difference a table makes: every row is measured against the same tracks, so the columns line up whatever each row happens to hold.
Implementation
List<double?> columns;