Reverse_mapping for cef input codec not working

Elastic Stack Logstash
2

The reverse_mapping option is for output. So

   output { stdout { codec => cef { reverse_mapping => false fields => [ "sourceAddress", "deviceCustomString4Label" ] } } }

will get you

CEF:0|Elasticsearch|Logstash|1.0|Logstash|Logstash|6|sourceAddress=10.1.100.17 deviceCustomString4Label=ICMP Type

and if you flip that to true you get

CEF:0|Elasticsearch|Logstash|1.0|Logstash|Logstash|6|src=10.1.100.17 cs4Label=ICMP Type