code: func deleteLeadingComments(ext string, buf []byte) []byte {
  	if ext != ".yaml" {
  		return buf
  	}
  
  	for {
  		buf = bytes.TrimLeftFunc(buf, unicode.IsSpace)
  		if buf[0] == '#' {
  			buf = deleteLine(buf)
  		} else {
  			break
  		}
  	}
  
  	return buf
  }
docs: // deleteLeadingComments deletes leading newlines and comments in buf.
  // It only works for ext == ".yaml".