Support numbers only file names about flutter_gen HOT 2 OPEN

 Could not format because the source could not be parsed:
  
  line 19, column 23 of .: Expected a class member.
     ╷
  19 │     AssetGenImage get 3Arrows => const AssetGenImage('assets/icons/3_arrows.png');
     │                       ^
     ╵
  line 19, column 24 of .: Methods must have an explicit list of parameters.
     ╷
  19 │     AssetGenImage get 3Arrows => const AssetGenImage('assets/icons/3_arrows.png');
     │                        ^^^^^^
     ╵
  line 19, column 19 of .: Expected to find ';'.
     ╷
  19 │     AssetGenImage get 3Arrows => const AssetGenImage('assets/icons/3_arrows.png');
     │                   ^^^
     ╵
  [INFO] Reading cached asset graph completed, took 325ms