anchor.diff:  
   For example, in order to include the `greeting` field created earlier  in the invoice creation email, you will need to do the following:
   
  -* Create an email template with the  `invoice.greeting` field as shown below and upload the new template as explained https://docs.killbill.io/latest/email-notification-plugin.html#_uploading_a_custom_template[here].
  +* Create an email template with the  `invoice.newInvoiceMessage` field as shown below and upload the new template as explained https://docs.killbill.io/latest/email-notification-plugin.html#_uploading_a_custom_template[here].
   [source,bash]
  -{{invoice.greeting}}
  +{{invoice.newInvoiceMessage}}
   
   * Trigger the invoice creation email as explained https://docs.killbill.io/latest/email-notification-plugin.html#_testing_the_plugin[here].
   
  
positive.code: 	
  	private static final Logger logger = LoggerFactory.getLogger(CustomInvoiceFormatter.class);
  	
  	private String greeting="Here is your new invoice!!";
  	
  	public String getGreeting() {
  		return greeting;
  	}
  
  }
  
negative.code: 
  * It has a constructor as shown above.
  
  * A field called `newInvoiceMessage` is defined. This is a custom field. It has a corresponding `getNewInvoiceMessage` method.
  
  * You can add other custom fields as required. For each field, ensure that the field is initialized and that there is a `getter` method that returns the value of the field. 
  
  