anchor.diff:  	  import_export/1, misc_attrs/1, dialyzer_attrs/1,
   	  hook/1,
   	  neg_indent/1,
  +	  maps_syntax/1,
   
   	  otp_6321/1, otp_6911/1, otp_6914/1, otp_8150/1, otp_8238/1,
   	  otp_8473/1, otp_8522/1, otp_8567/1, otp_8664/1, otp_9147/1,
  
positive.code: count_atom(_, _) ->
      0.
  
  otp_8567(doc) ->
      "OTP_8567. Avoid duplicated 'undefined' in record field types.";
  otp_8567(suite) -> [];
  
negative.code:     [{expr, [],
        [func, call, recs, try_catch, if_then, receive_after,
         bits, head_tail, cond1, block, case1, ops,
         messages, old_mnemosyne_syntax, maps_syntax
      ]},
       {attributes, [], [misc_attrs, import_export, dialyzer_attrs]},
       {tickets, [],
        [otp_6321, otp_6911, otp_6914, otp_8150, otp_8238,
  