anchor.diff:     { handleEndArgument(); }
      ;
   
  -   // added this to return non-EOF token type here. EOF does something weird
  +// added this to return non-EOF token type here. EOF does something weird
   UNTERMINATED_ARGUMENT
      : EOF -> popMode
      ;
  
positive.code: OPT_WS
     : Ws+ -> type (WS) , channel (OFF_CHANNEL)
     ;
     // -------------------------
  
  mode Tokens;
  TOK_DOC_COMMENT
     : DocComment -> type (DOC_COMMENT) , channel (COMMENT)
  
negative.code: TOK_WS
     : Ws+ -> type (WS) , channel (OFF_CHANNEL)
     ;
  
  // -------------------------
  mode Channels;
  // currently same as Tokens mode; distinguished by keyword
  CHN_DOC_COMMENT
  