public void setActionDefinition(StatelessCustomActionDefinition actionDefinition) {
        this.actionDefinition = actionDefinition;
    }
<p>
The definition of a custom action.
</p>

@param actionDefinition
       The definition of a custom action.
aws-java-sdk-securityhub/src/main/java/com/amazonaws/services/securityhub/model/RuleGroupSourceCustomActionsDetails.java