if (processDefinition == null) {
throw new ActivitiObjectNotFoundException("No process definition found for id '" + processDefinitionId + "'", ProcessDefinition.class);
}
ActivityImpl startActivity = processDefinition.findActivity(messageEventSubscription.getActivityId());
ExecutionEntity processInstance = processDefinition.createProcessInstance(businessKey, startActivity);
if (processVariables != null) {
processInstance.setVariables(processVariables);
}