code: def _ensure_features_time_axis(self) -> None:
      self.features = [
          c if c.startswith(self.time_axis) else f"{self.time_axis}:{c}"
          for c in self.features
      ]
  
imports: from pathlib import Path
  from typing import Any, Dict, List, Optional, Union
  import pandas
  from histogrammar.dfinterface.make_histograms import get_time_axes
  from pydantic import BaseModel
  from pydantic_settings import BaseSettings
  from typing_extensions import Literal
label_desc: Use image node_id 1 for calling the Settings obj's underlying member method code with example usage: obj._ensure_features_time_axis() without return types