old_contents: """
      ${NAME}
  """
  from __future__ import absolute_import, division, print_function, unicode_literals
  import logging
  log = logging.getLogger(__name__)
  
  class Layer:
      Blocks = "Blocks"
      Entities = "Entities"
      Monsters = "Monsters"
      MonsterLocations = "MonsterLocations"
      Items = "Items"
      TileEntities = "TileEntities"
      TileEntityLocations = "TileEntityLocations"
      CommandBlockColors = "CommandBlockColors"
      CommandBlockLocations = "CommandBlockLocations"
      ItemFrames = "ItemFrames"
      TileTicks = "TileTicks"
      TerrainPopulated = "TerrainPopulated"
      ChunkSections = "ChunkSections"
      AllLayers = (Blocks, Entities, Monsters, MonsterLocations, Items,
                   TileEntities, TileEntityLocations,
                   CommandBlockColors, CommandBlockLocations,
                   ItemFrames, TileTicks, ChunkSections)
      DefaultVisibleLayers = (Blocks, Entities, Items, TileEntities, CommandBlockColors, ItemFrames)
  
new_contents: """
      ${NAME}
  """
  from __future__ import absolute_import, division, print_function, unicode_literals
  import logging
  log = logging.getLogger(__name__)
  
  class Layer:
      Blocks = "Blocks"
      Entities = "Entities"
      Monsters = "Monsters"
      MonsterLocations = "MonsterLocations"
      Items = "Items"
      TileEntities = "TileEntities"
      TileEntityLocations = "TileEntityLocations"
      CommandBlockColors = "CommandBlockColors"
      CommandBlockLocations = "CommandBlockLocations"
      ItemFrames = "ItemFrames"
      TileTicks = "TileTicks"
      TerrainPopulated = "TerrainPopulated"
      ChunkSections = "ChunkSections"
      AllLayers = (Blocks, MonsterLocations, Items,
                   TileEntities, TileEntityLocations,
                   CommandBlockColors, CommandBlockLocations,
                   ItemFrames, TileTicks, ChunkSections)
      DefaultVisibleLayers = (Blocks, Items, TileEntities, CommandBlockColors, ItemFrames)
  
subject: Remove unused layers from AllLayers