code: func (c *Client) fileToSearchParams(path string, langs []string) (*[]interface{}, error) {
  	// File size
  	file, err := os.Open(path)
  	if err != nil {
  		return nil, err
  	}
  	defer file.Close()
  	fi, err := file.Stat()
  	if err != nil {
  		return nil, err
  	}
  	size := fi.Size()
  
  	// File hash
  	h, err := HashFile(file)
  	if err != nil {
  		return nil, err
  	}
  
  	params := []interface{}{
  		c.Token,
  		[]struct {
  			Hash  string `xmlrpc:"moviehash"`
  			Size  int64  `xmlrpc:"moviebytesize"`
  			Langs string `xmlrpc:"sublanguageid"`
  		}{{
  			hashString(h),
  			size,
  			strings.Join(langs, ","),
  		}},
  	}
  	return &params, nil
  }
docs: // Build query parameters for hash-based movie search.