There is no reference to any use of [fiveArgumentPooler](https://github.com/facebook/react/blob/32f5b034ed229d048f76ae74e18d270edc801dbf/src/shared/utils/PooledClass.js#L68) in the codebase. Deleted it without issue. Sending a Pull Request
* @param {Function} pooler Customizable pooler.
 */
var addPoolingTo = function<T>(
  CopyConstructor: Class<T>,
  pooler: Pooler,
): Class<T> & {
  getPooled(): T,
  release(): void,
} {
  
  
  var NewKlass = (CopyConstructor: any);
  NewKlass.instancePool = [];
  NewKlass.getPooled = pooler || DEFAULT_POOLER;
  if (!NewKlass.poolSize) {
    NewKlass.poolSize = DEFAULT_POOL_SIZE;
  }
  NewKlass.release = standardReleaser;
  return NewKlass;
};
var PooledClass = {
  addPoolingTo: addPoolingTo,
  oneArgumentPooler: (oneArgumentPooler: Pooler),
  twoArgumentPooler: (twoArgumentPooler: Pooler),
  threeArgumentPooler: (threeArgumentPooler: Pooler),
  fourArgumentPooler: (fourArgumentPooler: Pooler),
  fiveArgumentPooler: (fiveArgumentPooler: Pooler),
};
module.exports = PooledClass;