function PriorityQueue () {
    this.collection = []
    this.collectionObj = {}
    this.printCollection = function() {
      console.table(this.collection)
    }

    this.enqueue = ([str, prio]) => {

        if (this.isEmpty()) {
            this.collectionObj[prio] = [str]
            this.collection.push([str, +prio])
            return
        }

        if (!this.collectionObj[prio]) {
            this.collectionObj[prio] = [str]
        } else {
            this.collectionObj[prio].push(str)
        }

        this.collection = []
        let keys = Object.keys(this.collectionObj)

        keys.map(key => {
            if (this.collectionObj[key].length === 1) {
                this.collection.push([this.collectionObj[key][0], +key])
            } else {
                this.collectionObj[key].map(str => this.collection.push([str, +key]) )
            }

        })
    }

    this.dequeue = () => {
        let keys = Object.keys(this.collectionObj)
        let elToReturn

        if (this.collectionObj[keys[0]].length === 1) {
            elToReturn = this.collectionObj[keys[0]]
            delete this.collectionObj[keys[0]]
            this.collection.shift()
        } else {
            elToReturn = this.collectionObj[keys[0]][0]
            this.collectionObj[keys[0]].shift()
            this.collection.shift()
        }

        return elToReturn
    }

    this.front = () => this.collection[0]
    this.size = () => this.collection.length
    this.isEmpty = () => this.collection.length === 0
}