register-access.js

/**
 * Uses a map for keeping track of access and set operations. 
 */
_registerAccess(propertyName: string, isDefined: boolean): void {
  let register = {
    count: 0,
    called: false,
    isDefined
  };

  register.count++;
  register.called = true;
  this._spyMap.set(propertyName, register);
}