Groovy Script Engine creates new classes for each script and doesn't get garbage collected

New classes are created for each script:

https://github.com/groovy/groovy-core/blob/master/src/main/org/codehaus/groovy/jsr223/GroovyScriptEngineImpl.java#L109

Which are added to the classMap, which grows and old classes don't get garbage collected:

https://github.com/groovy/groovy-core/blob/master/src/main/org/codehaus/groovy/jsr223/GroovyScriptEngineImpl.java#L338

This results in PermGen errors:

Rexster Groovy Script Engine
https://github.com/tinkerpop/rexster/issues/143

Neo4j Server Groovy Script Engine
http://neo4j-community-discussions.438527.n3.nabble.com/Neo4j-Feedback-after-evaluation-tp3569774p3574520.html

There is no public way of removing older scripts and the HashMap is not a LinkedHashMap with LRU enabled for storing them. Right now the Neo4j workaround is to recreated the GSE every 500 requests.