Source: xxe/editor/SaveStateChangedEvent.js

/**
 * {@link XMLEditorEvent} sent whenenever the save state of the document 
 * being edited in an {@link XMLEditor} changes. 
 * Note that this may happen simply because the user has executed 
 * the undo command, reverting the document to its last saved state.
 */
export class SaveStateChangedEvent extends XMLEditorEvent {
    constructor(xmlEditor, data) {
        super(xmlEditor, data, "saveStateChanged");
    }

    /**
     * Get the <code>saveNeeded</code> property of this event:
     * tests whether the document being edited has changes 
     * which need to be saved.
     *
     * @type {boolean}
     */
    get saveNeeded() {
        return this._saveNeeded;
    }
}