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var count = 0
function WhoAmI(){
  count ++
  var res = document.getElementsByClassName('console')[0].innerHTML
  document.getElementsByClassName('console')[0].innerHTML = 
			`${res} <br/> ${count} I'm ${this.name} of ${typeof(this)}`
}

WhoAmI()                      // ①

let BillGates = {
  name: 'Bill Gates'
}
BillGates.WhoAmI = WhoAmI
BillGates.WhoAmI()            // ②

let SteveJobs = {
  name: 'Steve Jobs'
}
SteveJobs.WhoAmI = WhoAmI
SteveJobs.WhoAmI()            // ③

WhoAmI.call(BillGates)        // ④
WhoAmI.call(SteveJobs)        // ⑤

BillGates.WhoAmI.call(SteveJobs)   // ⑥
SteveJobs.WhoAmI.call(BillGates)   // ⑦

WhoAmI.WhoAmI = WhoAmI
WhoAmI.name = 'WhoAmI'
WhoAmI.WhoAmI()                    // ⑧

BillGates.WhoAmI.apply(SteveJobs)  // ⑨
SteveJobs.WhoAmI.apply(BillGates)  // ⑩