anchor.diff:  //create-user.html
   createUser
       : CREATE USER (IF NOT EXISTS)?
  -    user authOptions
  +    user authOptions?
       DEFAULT ROLE roles
       (REQUIRE (NONE | tlsOption (COMMA AND? tlsOption)*))?
       (WITH resourceOption (COMMA resourceOption)*)?
  
positive.code:     ;
  
  user
      : ID
      | STRING
      | STRING AT_ STRING
      ;
  
  users
  
negative.code:     ;
  
  role
      : STRING AT_ STRING
      | STRING
      | ID
      ;
  
  roles
  