function createNewLookupObject() {
	  for (var _len = arguments.length, sources = Array(_len), _key = 0; _key < _len; _key++) {
	    sources[_key] = arguments[_key];
	  }

	  return _utils.extend.apply(undefined, [_Object$create(null)].concat(sources));
	}
Create a new object with "null"-prototype to avoid truthy results on prototype properties.
The resulting object can be used with "object[property]" to check if a property exists
@param {...object} sources a varargs parameter of source objects that will be merged
@returns {object}