@ModuleOption("the time unit for the fixed and initial delays")
	public void setTimeUnit(String timeUnit) {
		this.timeUnit = timeUnit.toUpperCase();
	}
Mixin for options that include a periodic fixed-delay trigger.
fixedDelay remains in annotated classes to avoid breaking changes
due to differing defaults.

@author Gary Russell
spring-xd-module-spi/src/main/java/org/springframework/xd/module/options/mixins/PeriodicTriggerMixin.java