Returns a cell given its face (range 0..5), Hilbert curve position within
that face (an unsigned integer with S2CellId::kPosBits bits), and level
(range 0..kMaxLevel). The given position will be modified to correspond
to the Hilbert curve position at the center of the returned cell. This
is a static function rather than a constructor in order to indicate what
the arguments represent.
Returns a cell given its face (range 0..5), Hilbert curve position within that face (an unsigned integer with S2CellId::kPosBits bits), and level (range 0..kMaxLevel). The given position will be modified to correspond to the Hilbert curve position at the center of the returned cell. This is a static function rather than a constructor in order to indicate what the arguments represent.