ItemTypes.air not working

The ItemType air is not found anymore in Gametest Engine on version 1.0.0-beta.

Tested on Server-Alpha for Linux with Windows Edition as Client.

Steps to reproduce

1. Create a AddOn with Gametest Engine.
2. Add the followinging commandlines to the script:

import {world, ItemStack, MinecraftItemTypes} from "mojang-minecraft";

world.events.beforeChat.subscribe(() => {    
 try {        
  const stack = new ItemStack(MinecraftItemTypes.air);                                                world.getDimension("overworld").runCommand("msg @a Could get ItemStack");
    } catch (error) {       
 world.getDimension("overworld").runCommand("msg @a Could not get ItemStack")    
}
}) 

 
        3. Start a world with the addon and send a message via chat.
Observed Result

You recieve a message with: Could not get ItemStack

Expected Result

You recieve a message with: Could get ItemStack