code: func (c *Compressor) writeUncompressedBlock(d []byte) error {
  	if len(d) == 0 {
  		return nil
  	}
  	if err := c.writeVarUint(uint32(len(d))); err != nil {
  		return err
  	}
  	if n, err := c.w.Write(d); err != nil {
  		return err
  	} else {
  		c.outSize += n
  	}
  	return nil
  }
docs: // writeUncompressedBlock: writes out a block of uncompressed data
  // preceded by the length of the block as a variable length integer