If the MockServer is started using the Maven Plugin a initializationClass property can be specified to initialize expectations, when the MockServer starts.
Note: the plugin must be started during the process-test-classes to ensure that the initialization class has been compiled from either src/main/java or
src/test/java locations. In addition the initializer can only be used with start and run goals, it will not work with the runForked goal as a JVM is forked
with a separate classpath. (required: false, default: false)