 At the end of the stream, <code class="computeroutput"><span class="identifier">write</span></code>
          checks that its computed adler32 checksum is equal to that saved by the
          compressor and returns <code class="computeroutput"><span class="identifier">error</span><span class="special">::</span><span class="identifier">end_of_stream</span></code>
          only if the checksum is correct. This function returns no error if some
          progress has been made (more input processed or more o