CodegenConfigurator systemProperties are reused between code generation invokations

I'm using the swagger CodegenConfigurator in a gradle build where the swagger codegen project is loaded as a library and is being directly passed into the DefaultGenerator.

This usage in this gradle plugin is very similar to my usage.

If I configure one CodegenConfigurator object with systemProperties being set, these settings seem to be being stored somewhere statically.

I'm observing that if I use a new DefaultGenerator again in the same JVM I end up having files not get generated because of input from a previous run of the generator.

I know that the two CodegenConfigurator objects that I'm passing in are different because I've tested logging the systemProperties variable just before passing it in and for the first call it is populated and the second time it is empty.

Start with CodegenConfigurator and DefaultGenerator, then compare their state across two generation runs in the same JVM. Reproduce the Gradle-style usage described in the issue with one populated and one empty systemProperties map; done means the second run is unaffected by the first and generates files according to its own configuration.