An aggregate row (group footer / grand total) — the label lands on "the first empty cell"
(it used to check only foot[0], so the label went missing silently if the
first column had an aggregate); if every cell ends up with a value (every column has an
aggregate), the label is omitted — there's nowhere to put it without overwriting a total
returns undefined when no column declares an aggregate
An aggregate row (group footer / grand total) — the label lands on "the first empty cell" (it used to check only foot[0], so the label went missing silently if the first column had an aggregate); if every cell ends up with a value (every column has an aggregate), the label is omitted — there's nowhere to put it without overwriting a total returns undefined when no column declares an aggregate