{"error": {"errorMessage": "type object argument after ** must be a mapping, not NoneType", "errorType": "TypeError", "stackTrace": ["  File \"/opt/silvaengine_base/lambdabase.py\", line 47, in handler\n    return cls(*args, **kwargs).handle(event, context)\n", "  File \"/opt/silvaengine_base/worker.py\", line 54, in handle\n    params = self._prepare_params(event)\n", "  File \"/opt/silvaengine_base/worker.py\", line 82, in _prepare_params\n    for k, v in dict(\n"]}}