text: // Note: Variables created without the keyword var, are always global, even if
  // they are created inside a function.
  
  // Flavour 1 - closure ////////////////////////////////////////
  // In JavaScript, all functions have access to the scope "above"
  // them - so Flavour 1 works without the use of 'this'.
  // This is a closure - a function that has access to the parent scope, even
  // after the parent function has closed.
  // See here: https://www.w3schools.com/js/js_function_closures.asp
  //
  // function Plane() {
  //   var _Flying = true;
  //
  //   return {
  //     land: function() { _Flying = false; },
  //     isFlying: function() { return _Flying; }
  //   }
  // }
  
  // Flavour 2 ////////////////////////////////////////////////
  // function Plane() {
  //   this._Flying = true;
  //
  //   this.land = function() { this._Flying = false; },
  //   this.isFlying = function() { return this._Flying; }
  // }
  
  // Flavour 3 - prototypes ///////////////////////////////////
  function Plane() {
    this._Flying = true;
  }
  
   Plane.prototype = {
      land: function() { this._Flying = false; },
      isFlying: function() { return this._Flying; }
   }
  