createDataFromJSON() is failing with dataformats which are arrays of dictionaries of dictionaries

It seems that the method createDataFromJSON() from the DataFormatSerializer does not work well when we have a dataformat, which is a list of dictionaries of dictionaries.

E.g.:

{
    "objs": [2, 
      {   
        "id": "int32",
        "coordinates": {"x": "int32",
          "y": "int32"
        }   
      }   
    ]   
}

In this case, the method returns None and the associated error string is: Data instance has no attribute 'coordinates'

I've pushed a 'failing' unit test in the repository (b8d4d1bc and e489e67f)