`It must have been that,' said the King, `unless it was
written to nobody, which isn't usual, you know.'

  `Who is it directed to?' said one of the jurymen.

  `It isn't directed at all,' said the White Rabbit; `in fact,
there's nothing written on the OUTSIDE.'  He unfolded the paper
as he spoke, and added `It isn't a letter, after all:  it's a set
of verses.'

   * hang forever. More precisely, if it's expected to return, we simply call it[*], but if it's
   * expected to hang (because one of the input futures that we know makes it up isn't done yet),
   * then we call it in a separate thread (using pseudoTimedGet). The result is that we wait as long
   * as necessary when the method is expected to return (at the cost of hanging forever if there is

   * hold {@code expectedSize} elements without growth. This behavior cannot be broadly guaranteed,
   * but it is observed to be true for OpenJDK 1.7. It also can't be guaranteed that the method
   * isn't inadvertently <i>oversizing</i> the returned map.
   *
   * @param expectedSize the number of entries you expect to add to the returned map

  `It must have been that,' said the King, `unless it was
written to nobody, which isn't usual, you know.'

  `Who is it directed to?' said one of the jurymen.

  `It isn't directed at all,' said the White Rabbit; `in fact,
there's nothing written on the OUTSIDE.'  He unfolded the paper
as he spoke, and added `It isn't a letter, after all:  it's a set
of verses.'