#2007 P25 Call events tracking. P25 Traffic channel manager now uses event trackers to deconflict between control channel and traffic channel event updates. Protects against Motorola ISSI FQSUID that's all zeros. Resolves issue with running out of traffic channels after losing the control channel and going into CC hunt mode a few times. (#2010)

Co-authored-by: Dennis Sheirer <dsheirer@github.com>

src/main/java/io/github/dsheirer/identifier/IdentifierCollection.java

@@ -363,6 +363,15 @@ public class IdentifierCollection
         return to;
     }
 
+    /**
+     * Returns an encryption key identiier or null.
+     * @return key or null.
+     */
+    public Identifier getEncryptionIdentifier()
+    {
+        return getIdentifier(IdentifierClass.USER, Form.ENCRYPTION_KEY, Role.ANY);
+    }
+
     @Override
     public String toString()
     {