Failed to recreate a list

[HolQue]

In the following JSON code a list is recreated:

"A" : [1,  2],
"A" : [3,  4]

Result:

Error: 'argument of type 'int' is not iterable

But expected:

"A" with value [3, 4]

Cross check

The same with a dictionary:

"B" : {"param1" : 1},
"B" : {"param2" : 1}

Result (like expected):

DotDict({'B': DotDict({'param2': 1})})