anchor.diff:      await read(2, 3, 1, [null, null, 1]);
       await read(0, 0, 0, [null, null, null]);
   
  +    await openedFile.close();
  +
       asyncTestDone("testReadInto");
     }
   
  
positive.code: 
      var bytesFromFile = await file.readAsBytes();
      Expect.listEquals(result, bytesFromFile);
      asyncTestDone("testWriteFrom");
    }
  
  
negative.code: 
      var bytesFromFile = file.readAsBytesSync();
      Expect.listEquals(result, bytesFromFile);
  
      openedFile.closeSync();
    }
  
    // Tests exception handling after file was closed.
  