true" title="class or interface in java.lang" class="externalLink">Cloneable</a>, <a href="https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/io/Serializable.html?is-external=true" title="class or interface in java.io" class="externalLink">Serializable</a></pre>
<div class="block">The Flags class represents the set of flags on a Message.  Flags
 are composed of predefined system flags, and user defined flags. <p>

 A System flag is represented by the <code>Flags.Flag</code> 
 inner class. A U