code: def __init__(self):
      super().__init__("always_one")
  
file_path: mmf/tests/data/user_dir/datasets/always_one.py
imports: from mmf.common.registry import registry
  from mmf.datasets.base_dataset_builder import BaseDatasetBuilder
  from tests.test_utils import NumbersDataset
label_desc: Use image node_id 1 to create a new AlwaysOneBuilder object from inherited base classes: BaseDatasetBuilder with example: obj = AlwaysOneBuilder()