wijmo.angular2.grid.multirow is an external TypeScript module that can be imported to your code using its ambient module name. For example:

import * as wjMultiRow from 'wijmo/wijmo.angular2.grid.multirow';
 
@Component({
    directives: [wjMultiRow.WjMultiRow],
    template: `<wj-multi-row></wj-multi-row>`,
    selector: 'my-cmp',
})
export class MyCmp {
}