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
var Klass = this;
  if (Klass.instancePool.length) {
    var instance = Klass.instancePool.pop();
    Klass.call(instance, a1, a2, a3, a4, a5);
    return instance;
  } else {
    return new Klass(a1, a2, a3, a4, a5);
  }
};
var standardReleaser = function(instance) {
  var Klass = this;
  invariant(
    instance instanceof Klass,
    'Trying to release an instance into a pool of a different type.'
  );
  instance.destructor();
  if (Klass.instancePool.length < Klass.poolSize) {
    Klass.instancePool.push(instance);
  }
};
var DEFAULT_POOL_SIZE = 10;
var DEFAULT_POOLER = oneArgumentPooler;
type Pooler = any;
/**
 * Augments `CopyConstructor` to be a poolable class, augmenting only the class
 * itself (statically) not adding any prototypical fields. Any CopyConstructor
 * you give this may have a `poolSize` property, and will look for a
 * prototypical `destructor` on instances.
 *
 * @param {Function} CopyConstructor Constructor that can be used to reset.