anchor.diff:      ?WAIT100,
       undefined = val(item, player),
       Helmet = val(item, head1),
  -    Head = val(body_part, Helmet),
  -    Head = val(body_part, DexBuff),
  +    {Head, head} = val(body_part, Helmet),
  +    {Head, head} = val(body_part, DexBuff),
       attempt(Config, Player, {move, <<"helmet">>, from, <<"head">>, to, Player}),
       ?WAIT100,
  +    %% TODO this doesn't make any sense for the player to have a single item
       Helmet = val(item, player),
       undefined = val(body_part, Helmet),
       undefined = val(body_part, DexBuff),
  
positive.code:     ?WAIT100,
      undefined = val(item, player),
      Helmet = val(item, head1),
      Head = val(body_part, Helmet),
      Head = val(body_part, DexBuff),
      attempt(Config, Player, {move, <<"helmet">>, from, current_body_part, to, Player}),
      ?WAIT100,
      Helmet = val(item, player),
      undefined = val(body_part, Helmet),
      undefined = val(body_part, DexBuff),
      undefined = val(item, head1).
  
negative.code:     ?WAIT100,
      undefined = val(item, Player),
      Helmet = val(item, head1),
      {Head, head} = val(body_part, Helmet).
  
  player_wield_missing_body_part(Config) ->
      start(?WORLD_4),
  