clustering/common/src/main/java/org/jboss/as/clustering/controller/Operations.java
public static ModelNode getAttributeValue(ModelNode operation) {
        return operation.hasDefined(ModelDescriptionConstants.VALUE) ? operation.get(ModelDescriptionConstants.VALUE) : new ModelNode();
    }
public static ModelNode getAttributeValue(ModelNode operation) {
        return operation.hasDefined(ModelDescriptionConstants.VALUE) ? operation.get(ModelDescriptionConstants.VALUE) : new ModelNode();
    }
Returns the attribute value of the specified operation
@param operation an operation
@return an attribute value