Initialize a TrainingDataSet object from a json dictionary.

def _from_dict(cls, _dict):
        """Initialize a TrainingDataSet object from a json dictionary."""
        args = {}
        if 'environment_id' in _dict:
            args['environment_id'] = _dict.get('environment_id')
        if 'collection_id' in _dict:
            args['collection_id'] = _dict.get('collection_id')
        if 'queries' in _dict:
            args['queries'] = [
                TrainingQuery._from_dict(x) for x in (_dict.get('queries'))
            ]
        return cls(**args)