public void setScheduleExpression(String scheduleExpression) {
        this.scheduleExpression = scheduleExpression;
    }
<p>
A cron expression when the association will be applied to the targets.
</p>

@param scheduleExpression
       A cron expression when the association will be applied to the targets.
aws-java-sdk-ssm/src/main/java/com/amazonaws/services/simplesystemsmanagement/model/CreateAssociationRequest.java