old_contents: from collections import namedtuple
  
  # Note: we may want to have an implicit parameter to distinguish between
  # locations that are near or far. This way, the difficulty level would be
  # implicitly represented in instructions.
  
  # action: goto, open, pick, drop
  Instr = namedtuple('Instr', ['action', 'object'])
  
  # loc: RelLoc, AbsLoc
  # state: locked
  Object = namedtuple('Object', ['type', 'color', 'loc', 'state'])
  
  # Relative locations
  # loc: left, right, front, behind
  RelLoc = namedtuple('RelLoc', ['loc'])
  
  # Absolute locations
  # loc: north, south, east, west
  AbsLoc = namedtuple('RelLoc', ['loc'])
  
new_contents: from collections import namedtuple
  
  # Note: we may want to have an implicit parameter to distinguish between
  # locations that are near or far. This way, the difficulty level would be
  # implicitly represented in instructions.
  
  # action: goto, open, pick, drop
  Instr = namedtuple('Instr', ['action', 'object'])
  
  # loc: RelLoc, AbsLoc
  # state: locked
  Object = namedtuple('Object', ['type', 'color', 'loc', 'state'])
  
  # Relative locations
  # loc: left, right, front, behind
  RelLoc = namedtuple('RelLoc', ['loc'])
  
  # Absolute locations
  # loc: north, south, east, west
  AbsLoc = namedtuple('AbsLoc', ['loc'])
  
subject: fix typo