// contract.
    // This is somewhat annoying, but turns out to be very fast in practice. Alternatively, we could
    // drop the contract on the method that enforces this queue like behavior since depending on it
    // is likely to be a bug anyway.

    // N.B. All writes to the list and the next pointers must have happened before the above

   * other, pass it first. Unfortunately, since this method sets the generic type of the returned
   * set based on the type of the first set passed, this could in rare cases force you to make a
   * cast, for example:
   *
   * <pre>{@code
   * Set<Object> aFewBadObjects = ...
   * Set<String> manyBadStrings = ...
   *
   * // impossible for a non-String to be in the intersection