code: function copyOwnProperties(source, target, ignorePropertyNames = []) {
    Object.getOwnPropertyNames(source).forEach(name => {
      if (ignorePropertyNames.indexOf(name) < 0) {
        const descriptor = Object.getOwnPropertyDescriptor(source, name);
        Object.defineProperty(target, name, descriptor);
      }
    });
    return target;
  }
docs: /*
  Copy the given properties/methods to the target.
  Return the updated target.