default UIComponent asUIComponent() {
        if (this instanceof UIComponent) {
            return (UIComponent) this;
        }
        throw new UnsupportedOperationException(getClass().getName() + "#asUIComponent is not implemented");
    }
Special {@link #getColumnKey()} method which must be used when we are inside e.g.
the DataTable "row state".

@param parent
@param rowKey
@return
primefaces/src/main/java/org/primefaces/component/api/UIColumn.java