The written formulas, one per block of the same formula.
Blocks past blocks.
Cells in written.
Written cells that are now empty.
Written cells that now hold a formula.
What the write replaced, from the sheet as it was: populated cells and formulas among the
written ones. null when it cannot be told: the commit moved cells, or the store no longer
keeps the state before it.
The sheet, quoted as a reference would quote it.
The inserts and deletes of cells, in the order they ran.
Ranges whose formatting changed, or null.
Written cells that now hold a value that is not a formula.
The cells whose values or formulas were written, or null when none were.
What a commit did to one sheet.