在dragula的sort方法中添加类型断言

例如：

import { Directive, Input, ElementRef } from '@angular/core';
import * as dragula from 'dragula';

@Directive({
  selector: '[dragulaModel]'
})
export class DragulaDirective {
  @Input('dragulaModel') model: any[];
  @Input() dragulaOptions: any;

  private container: any;

  constructor(private el: ElementRef) {
    this.container = el.nativeElement;
  }

  ngOnInit() {
    var drake = dragula([this.container], this.dragulaOptions);

    drake.models.push(this.model);
    // 添加类型断言
    drake.on('drop', (args: any) => {
      this.model = this.container['parentNode'][this.dragulaOptions.modelName];
    });
  }
}