Wordpress Boilerplate - Ajax with plugin

I'm working on to writing a Wordpress Plugin based on: http://wppb.io/

My issue is: I'm working on Public view and try to use Ajax to connect with backend.I'm use: public/js/ xxx-public.js to place all ajax function handle and Define some hooks:

    wp_enqueue_script( $this->plugin_name, plugin_dir_url( __FILE__ ) . 'js/xxx-public.js', array( 'jquery' ), $this->version, false );

    wp_register_script( 'district_handle', plugin_dir_url( __FILE__ ) . 'js/xxx-public.js', array( 'jquery' ), $this->version, false );
    wp_enqueue_script( 'district_handle');

    wp_register_script( 'ret_cus_handle', plugin_dir_url( __FILE__ ) . 'js/xxx-public.js' , array( 'jquery' ), $this->version, false);
    wp_enqueue_script( 'ret_cus_handle');

    wp_register_script( 'order_ret_cus_handle', plugin_dir_url( __FILE__ ) . 'js/xxx-public.js', array( 'jquery' ), $this->version, false );
    wp_enqueue_script( 'order_ret_cus_handle'); 

It works.

But problem is: the website will generate 4 xxx-public.js in header. I only want one.

I'm just a newbie with WP plugin. I hope to get your solution. Thank you in advance

via Chebli Mohamed