code: def __init__(
      self,
      dvcfile: "SingleStageFile",
      stage_data: Dict[Any, str],
      stage_text: Optional[str] = None,
  ):
      self.dvcfile = dvcfile
      self.stage_data = stage_data or {}
      self.stage_text = stage_text
  
imports: from collections.abc import Mapping
  from copy import deepcopy
  from itertools import chain
  from typing import TYPE_CHECKING, Any, Dict, Iterable, Optional, Tuple
  from funcy import get_in, lcat, once, project
  from dvc import dependency, output
  from dvc.log import logger
  from dvc.parsing import FOREACH_KWD, JOIN, MATRIX_KWD, EntryNotFound
  from dvc.utils.objects import cached_property
  from dvc_data.hashfile.meta import Meta
  from .None import PipelineStage, Stage, loads_from
  from .exceptions import StageNameUnspecified, StageNotFound
  from .params import StageParams
  from .utils import fill_stage_dependencies, resolve_paths
label_desc: Use image node_id 1 to create a new SingleStageLoader object from inherited base classes: Mapping with example: obj = SingleStageLoader(dvcfile, stage_data, stage_text)