code: func (c *C2) Truncate(byteCount int) (evicted []byte) {
  	max := c.maxWritten()
  
  	if byteCount > max {
  		byteCount = max
  	}
  
  	bufferToRead := c.getBlockBuffer()
  	start := bufferToRead.head - max
  
  	c.totalWritten = c.maxWritten() - byteCount
  	return bufferToRead.buffer[start : start+byteCount]
  }
docs: // Shortens the content of the circular buffer
  // and returns the content removed