The fill command of nether_wart [ "age" = 15 ] returns an invalid value for "age".

Observed Result

• When I type /fill ~ ~ ~ ~ ~ ~ nether_wart [ "age" = 15 ], it logs "Invalid value for 'age'" and the Nether Wart is not placed.
  The argument "age" appears in the input suggestions, so it is possible that the data was lost?

Expected Result

• It should be usable since it appears in the input suggestions.
  The command to change the growth level is useful, so please make the "age" command available!