code: func (m Type) Suffix() string {
  	if m.fileSuffix != "" {
  		return m.fileSuffix
  	}
  	if len(m.Suffixes) > 0 {
  		return m.Suffixes[0]
  	}
  	// There are MIME types without file suffixes.
  	return ""
  }
docs: // Suffix returns the file suffix without any delmiter prepended.