Method increment

lib/generic-bar.js:204–214

(arg0 = 1, arg1 = {})

    // increment(delta, payload)
    // increment(payload)
    increment(arg0 = 1, arg1 = {}){
        // increment([payload]) => step=1
        // handle the use case when `step` is omitted but payload is passed
        if (typeof arg0 === 'object') {
            this.update(this.value + 1, arg0);
        
        // increment([step=1], [payload={}])
        }else{
            this.update(this.value + arg0, arg1);
        }
    }

    // get the total (limit) value
    getTotal(){