// For simplicity the rest of this description will discuss Futures.catching since it is the
  // simplest instance, though very similar descriptions apply to many other classes in this file.
  //
  // In the constructor of AbstractCatchingFuture, the delegate future is assigned to a field
  // 'inputFuture'. That field is non-final and non-volatile. There are 2 places where the
  // 'inputFuture' field is read and where we will have to consider visibility of the write