anchor.diff:    <facility>gelf-java</facility>
     <additionalField>application=MyApplication</additionalField>
     <additionalField>environment=development</additionalField>
  -</appender>
  ---
  -
  -
  -=== Customize GELF messages
  -
  -If you want to customize the GELF messages sent by the appender, you can
  -replace the class that converts log events to GELF messages with your own
  -implementation. Define a class implementing the `GelfMessageFactory`
  -interface. Alternatively, you may extend the `DefaultGelfMessageFactory`
  -class, which implements this interface.
  -
  -Configure the custom GELF message factory in the appender:
  -[source,xml]
  ---
  -<appender name="GRAYLOG2" class="com.github.pukkaone.gelf.logback.GelfAppender">
  -  ...
  -  <marshaller class="com.example.MyGelfMessageFactory">
  -    <mdcTimestampProperty>ReceivedDateTime</mdcTimestampProperty>
  -  </marshaller>
  -  ...
   </appender>
   --
   
  
positive.code: <dependency>
    <groupId>com.github.pukkaone</groupId>
    <artifactId>logback-gelf</artifactId>
    <version>1.1.6</version>
  </dependency>
  --
  
  
negative.code: 
  `sslTrustAllCertificates`::
      Skip SSL server certificate validation; default false (*optional*)
  
  
  === Customize GELF messages
  
  If you want to customize the GELF messages sent by the appender, you can
  replace the class that converts log events to GELF messages with your own
  implementation. Define a class implementing the `GelfMessageFactory`
  interface. Alternatively, you may extend the `DefaultGelfMessageFactory`
  class, which implements this interface.
  
  Configure the custom GELF message factory in the appender:
  [source,xml]
  --
  <appender name="GRAYLOG2" class="com.github.pukkaone.gelf.logback.GelfAppender">
    ...
    <marshaller class="com.example.MyGelfMessageFactory">
      <mdcTimestampProperty>ReceivedDateTime</mdcTimestampProperty>
    </marshaller>
    ...
  </appender>
  --
  