Array or JSON Object Process Variable

Got it to work by injecting my type into config. See below. Is there a reason that there is no method on the ProcessEngineConfiguration interface. Not sure why I needed to use the Impl class:

ProcessEngineConfiguration cfg = new StandaloneProcessEngineConfiguration()
.setJdbcUrl(“jdbc:h2:mem:flowable;DB_CLOSE_DELAY=-1”)
.setJdbcUsername(“sa”)
.setJdbcPassword("")
.setJdbcDriver(“org.h2.Driver”)
.setDatabaseSchemaUpdate(ProcessEngineConfiguration.DB_SCHEMA_UPDATE_TRUE);

	//cfg.getDef	
		
  ProcessEngineConfigurationImpl processEngineConfig = (ProcessEngineConfigurationImpl)cfg;
  processEngineConfig.initVariableTypes();
  processEngineConfig.getVariableTypes().addType(new CustomObjectType("camelbody", CamelBody.class));

  ProcessEngine processEngine =  processEngineConfig.buildProcessEngine();