The class plstream (and the other abstraction classes in
      plstream.h) provided in PLplot 4.99j (alpha) are to be
      considered as works in progress.  By the standards outlined above, the
      work has barely begun.  At this time, plstream is mostly a one
      to one mirror of the C API, which is to say, it is still far from the
      goals of simplification and abstraction outlined above.  As such, it
      can be expected to change radically over the course of time.  (We
      don't quote schedules--how long have you been waiting for 5.0?  :-).
    
      In any event, we would welcome improvement submissions along the lines
      of those above, but we would strongly discourage people from using
      plstream if they are expecting it to be rock solid.  It
      will
      be changing, to become more like the design goals elucidated above.
    
      So, if you like the ideas described above, and are willing to accept
      the burden of "upgrading" your code as the class plstream
      evolves, then feel free to use it.  Just don't whine when I fix some
      of the methods to take references instead of pointers, when I
      eliminate some of the redundant methods to use the collapsed form,
      etc.