old_contents: from pathlib import Path
  from tempfile import TemporaryDirectory
  from typing import Optional, TYPE_CHECKING
  
  if TYPE_CHECKING:
      from __init__ import BoardType
  
  __all__ = ["FakeBacklightSysfs"]
  
  
  def detect_board_type() -> Optional["BoardType"]:
      from . import BoardType
  
      model_file = Path("/proc/device-tree/model")
      try:
          model = model_file.read_text()
      except OSError:
          return None
      # Tinker Board 2/2S starts with ASUS Tinker Board 2 or ASUS Tinker Board 2S
      if model.rfind("Tinker Board 2"):
          return BoardType.TINKER_BOARD_2
      # Tinker Board 1/1S starts with Rockchip RK3288 Asus Tinker Board or Rockchip RK3288 Asus Tinker Board S
      elif model.rfind("Tinker Board"):
          return BoardType.TINKER_BOARD
      # Raspberry Pi starts with Raspberry Pi
      elif model.rfind("Raspberry Pi"):
          return BoardType.RASPBERRY_PI
      else:
          return None
  
  
  class FakeBacklightSysfs:
      """Context manager to create a temporary "fake sysfs" containing all relevant files.
      Used for tests and emulation.
  
      >>> with FakeBacklightSysfs() as backlight_sysfs:
      ...     backlight = Backlight(backlight_sysfs_path=backlight_sysfs.path)
      ...     # use `backlight` as usual
      """
  
      def __init__(self) -> None:
          self._temp_dir = TemporaryDirectory()
          self.path = Path(self._temp_dir.name)
  
      def __enter__(self) -> "FakeBacklightSysfs":
          files = {"bl_power": 0, "brightness": 255, "max_brightness": 255}
          for filename, value in files.items():
              (self.path / filename).write_text(str(value))
          Path(self.path / "actual_brightness").symlink_to(self.path / "brightness")
          return self
  
      def __exit__(self, *_) -> None:
          self._temp_dir.cleanup()
  
new_contents: from pathlib import Path
  from tempfile import TemporaryDirectory
  from typing import Optional, TYPE_CHECKING
  
  if TYPE_CHECKING:
      from __init__ import BoardType
  
  __all__ = ["detect_board_type", "FakeBacklightSysfs"]
  
  
  def detect_board_type() -> Optional["BoardType"]:
      from . import BoardType
  
      model_file = Path("/proc/device-tree/model")
      try:
          model = model_file.read_text()
      except OSError:
          return None
      # Tinker Board 2/2S starts with ASUS Tinker Board 2 or ASUS Tinker Board 2S
      if model.rfind("Tinker Board 2"):
          return BoardType.TINKER_BOARD_2
      # Tinker Board 1/1S starts with Rockchip RK3288 Asus Tinker Board or Rockchip RK3288 Asus Tinker Board S
      elif model.rfind("Tinker Board"):
          return BoardType.TINKER_BOARD
      # Raspberry Pi starts with Raspberry Pi
      elif model.rfind("Raspberry Pi"):
          return BoardType.RASPBERRY_PI
      else:
          return None
  
  
  class FakeBacklightSysfs:
      """Context manager to create a temporary "fake sysfs" containing all relevant files.
      Used for tests and emulation.
  
      >>> with FakeBacklightSysfs() as backlight_sysfs:
      ...     backlight = Backlight(backlight_sysfs_path=backlight_sysfs.path)
      ...     # use `backlight` as usual
      """
  
      def __init__(self) -> None:
          self._temp_dir = TemporaryDirectory()
          self.path = Path(self._temp_dir.name)
  
      def __enter__(self) -> "FakeBacklightSysfs":
          files = {"bl_power": 0, "brightness": 255, "max_brightness": 255}
          for filename, value in files.items():
              (self.path / filename).write_text(str(value))
          Path(self.path / "actual_brightness").symlink_to(self.path / "brightness")
          return self
  
      def __exit__(self, *_) -> None:
          self._temp_dir.cleanup()
  
subject: Add detect_board_type to __all__