Added handling for more null values

bin/tdlib_gen.dart

@@ -1,4 +1,5 @@
 import 'dart:io';
+import 'dart:typed_data';
 
 import 'tl_scheme.dart';
 
@@ -188,7 +189,14 @@ String findFromJsonHandling(
       objectPrefix: objectPrefix,
       varNameInsteadOfKeyName: 'e',
     );
-    return '($varAccess as List<dynamic>).map((e) => ($innerHandler)).toList(growable: false)';
+    final innerType = findDartType(
+      tmp2,
+      scheme,
+      abstractPrefix: abstractPrefix,
+      functionPrefix: functionPrefix,
+      objectPrefix: objectPrefix,
+    );
+    return '$varAccess == null ? <$innerType>[] : ($varAccess as List<dynamic>).map((e) => ($innerHandler)).toList(growable: false)';
   }
 
   final predefined = {
@@ -213,7 +221,7 @@ String findFromJsonHandling(
     return "int.parse($varAccess ?? '0')";
   }
   else if (type == 'bytes') {
-    return 'base64.decode($varAccess)';
+    return '$varAccess == null ? Uint8List(0) : base64.decode($varAccess)';
   }
   else {
     return 'b.TdBase.fromJson($varAccess) as ${findDartType(type, scheme, abstractPrefix: abstractPrefix, functionPrefix: functionPrefix, objectPrefix: objectPrefix)}';