Github user dankirkd commented on the issue:
https://github.com/apache/logging-log4j2/pull/110
Does this support variable replacement.
i.e. in PatternLayout one can do something like this:
`<Pattern>%d{ISO8601}{UTC} %d{Z}{UTC} [CID:%X{conversation-id}] [%t] %-5p
%c{1.} - %m%n</Pattern>`
But it seems that
`<KeyValuePair key="CID" value="%X{conversation-id}"/>`
or even
`<KeyValuePair key="CID" value="${conversation-id}"/>`
doesn't work.---
