public WorkflowSystemTask get(String taskType) {
        return Optional.ofNullable(registry.get(taskType))
                .orElseThrow(
                        () ->
                                new IllegalStateException(
                                        taskType + "not found in " + getClass().getSimpleName()));
    }
A container class that holds a mapping of system task types {@link
com.netflix.conductor.common.metadata.tasks.TaskType} to {@link WorkflowSystemTask} instances.
core/src/main/java/com/netflix/conductor/core/execution/tasks/SystemTaskRegistry.java