[LOG4J2-1807][core] Add and implement LogEvent.toImmutable().
[LOG4J2-1807][core] Add and implement LogEvent.toImmutable().
codescale/logging-log4j2,GFriedrich/logging-log4j2,xnslong/logging-log4j2,xnslong/logging-log4j2,codescale/logging-log4j2,xnslong/logging-log4j2,apache/logging-log4j2,GFriedrich/logging-log4j2,codescale/logging-log4j2,GFriedrich/logging-log4j2,apache/logging-log4j2,apache/logging-log4j2