code: function copyProperties (source, destination) {
    var props = Object.getOwnPropertyNames(source);
    props.forEach(function (prop) {
      var desc;
      if (!destination[prop]) {
        desc = Object.getOwnPropertyDescriptor(source, prop);
        destination[prop] = {value: source[prop], writable: desc.writable};
      }
    });
  }
docs: It copies the properties from source to destination object if they don't
  exist already.
  
  @param {object} source - The object where properties are copied from.
  @param {type} destination - The object where properties are copied to.