Any returns true if any bit in the Nulls is set, otherwise it will return false.

XXX old API returns nsp, which is broken -- we update in place.

FilterCount returns the number count that appears in both nsp and sel.

Or performs union operation on Nulls nsp,m and store the result in r.

Range adds the numbers in nsp starting at start and ending at end to m.

Set performs union operation on Nulls nsp,m and store the result in nsp.

Size estimates the memory usage of the Nulls.