init (...args) {
    super.init(...args)

    if (this.options.deferUrl) {
      this.options.url = this.options.deferUrl
    }
  }
When using server-side processing, the default mode of operation for
bootstrap-table is to simply throw away any data that currently exists in the
table and make a request to the server to get the first page of data to
display. This is fine for an empty table, but if you already have the first
page of data displayed in the plain HTML, it is a waste of resources. As
such, you can use data-defer-url instead of data-url to allow you to instruct
bootstrap-table to not make that initial request, rather it will use the data
already on the page.

@author: Ruben Suarez
@webSite: http://rubensa.eu.org
@update zhixin wen <wenzhixin2010@gmail.com>