docx-js/src/file/custom-properties/custom-properties-attributes.ts

import { XmlAttributeComponent } from "file/xml-components";

export class CustomPropertiesAttributes extends XmlAttributeComponent<{
    readonly xmlns: string;
    readonly vt: string;
}> {
    protected readonly xmlKeys = {
        xmlns: "xmlns",
        vt: "xmlns:vt",
    };
}