class PermessageDeflate::Session

def get_deflate
  return @deflate if @deflate
  window_bits = [@own_window_bits, MIN_WINDOW_BITS].max
  deflate     = Zlib::Deflate.new(@level, -window_bits, @mem_level, @strategy)
  @deflate = deflate if @own_context_takeover
  deflate
end