const obj = Object.create(null)
console.info([
  // true
  Object.isExtensible(obj),
  // false
  obj instanceof Object,
  // TypeError: obj.hasOwnProperty is not a function
  // obj.hasOwnProperty('key'),
  // false
  Object.prototype.hasOwnProperty.call(bar, 'key'),
])

Object.defineProperty(obj, 'key', {value: 1})
// true
console.info(Object.prototype.hasOwnProperty.call(obj, 'key'))