Registering property class without Spring

I’ve been looking at the example in camunda-bpm-examples/multi-tenancy/tenant-identifier-shared-definitions and am struggling to register a property when not using Spring.

In the second section of this example ( it shows how you can use an expression in the BPMN file to refer to and call a method in bean class. I assume that this is a Spring bean. However we are only using a Tomcat based distribution. While I have managed to register plug-ins without Spring I cannot find any examples of how to register properties. The question is, is it possible, or am hunting for something that is not supported?

Thanks in anticipation.