anchor.diff:    }
   
     /**
  -  * @hint functions like header(), except it adds the header to the **current** personalization envelope. You can set a header by providing the header and value, or by passing in a struct.
  +  * @hint functions like `header()`, except it adds the header to the **current** personalization envelope. You can set a header by providing the header and value, or by passing in a struct.
     * @header Facilitates two means of setting a header. You can pass in a struct with a key/value pair for the name and value of the header. Alternatively, you can use this to pass in the name of the header, and provide the value as a second argument.
     */
     public any function withHeader( any header, any value ) {
  
positive.code:   /**
    * @hint Sets the subject for the **current** personalization envelope. This overrides the global email subject for these recipients. A basic personalization envelope (with a 'to' recipient) needs to be in place before this can be added.
    */
    public any function withSubject ( required string subject ) {
      var count = countPersonalizations();
  
      //not sure to what extent I should validate
  
negative.code:   }
  
    /**
    * @hint functions like `customArg()`, except it adds the custom argument to the **current** personalization envelope.
    * @arg Facilitates two means of setting a custom argument. You can pass in a struct with a key/value pair, for example, { "Team": "Engineering" }, or you can use this to pass in the custom argument's name, and provide the value as a second argument.
    */
    public any function withCustomArg( required any arg, any value ) {
  