docs: def writeBinary (self, filename=None):
      """Writes a binary representation of this sequence to the given filename
      (defaults to self.binpath).
      """
      if filename is None:
        filename = self.binpath
  
      with open(filename, 'wb') as output:
        # Magic Number
        output.write( struct.pack('>H', Seq.Magic          )  )
        # Upload Type
        output.write( struct.pack('B', 9                   )  )
        # Version
        output.write( struct.pack('B', self.version        )  )
        # Number of Commands
        output.write( struct.pack('>H', len(self.commands) )  )
        # Sequence ID
        output.write( struct.pack('>H', self.seqid         )  )
        # CRC Placeholder
        output.write( struct.pack('>I', 0                  ) )
  
        pad = struct.pack('B', 0)
        for n in range(20):
          output.write(pad)
  
        for line in self.lines:
          output.write( line.encode() )
  
      self.crc32 = util.crc32File(filename, 0)
  
      with open(filename, 'r+b') as output:
        output.seek(28)
        output.write( struct.pack('>I', self.crc32) )