'More timer' extension

[MA-master-sec]

In common scratch there's only one timer to use
That's very inconvenient
so I make this code:

(function(Scratch) {
    'use strict';
    const vm = Scratch.vm;

    let timer = {};

    class Moretimer {
        
        getInfo () {
            return {
                color1:"#7f7f7f",
                id:"timer",
                name:"more timer",
                blocks:[
                {
                    opcode:"clear_all",
                    blockType:Scratch.BlockType.COMMAND,
                    text:"clear all timer"
                },
                {
                    opcode:"clear",
                    blockType:Scratch.BlockType.COMMAND,
                    text:"start or reset timer[T]",
                    arguments:{
                        T:{
                            type:Scratch.ArgumentType.STRING,
                            defaultValue: "mytimer",
                        }
                    }
                },
                {
                    opcode:"get",
                    blockType:Scratch.BlockType.REPORTER,
                    text:"timer[T]",
                    arguments:{
                        T:{
                            type:Scratch.ArgumentType.STRING,
                            defaultValue:"mytimer",
                        }
                    }
                }
                ]
            };
        }  
        clear_all(args, util){
            timer = {};
        }
        clear(args, util){
            timer[args.T.toString()] = Date.now();
        }
        get(args, util){
            return (Date.now() - timer[args.T.toString()]) / 1000;
        }
    }
    Scratch.extensions.register(new Moretimer());
})(Scratch);

It's just a easy code,but it makes the project convenient