How to use the alloyeditor.SelectionTest function in alloyeditor

constructor(config) {
        this.name = 'text';
        this.buttons = [
            this.getStyles(config.customStyles),
            'ezbold',
            'ezitalic',
            'ezunderline',
            'ezsubscript',
            'ezsuperscript',
            'ezquote',
            'ezstrike',
            'ezlink',
        ];

        this.test = AlloyEditor.SelectionTest.text;
    }

constructor(config) {
        super(config);

        this.name = 'text';
        this.buttons = this.getButtons(config);

        this.test = AlloyEditor.SelectionTest.text;
    }

constructor() {
        this.name = 'link';
        this.buttons = [
            'ezlinkedit',
        ];

        this.test = AlloyEditor.SelectionTest.link;
    }

constructor(config) {
        super(config);

        this.name = 'link';
        this.buttons = this.getButtons(config);

        this.test = AlloyEditor.SelectionTest.link;
    }