code: function extension (type) {
    if (!type || typeof type !== 'string') {
      return false
    }
  
    // TODO: use media-typer
    var match = EXTRACT_TYPE_REGEXP.exec(type)
  
    // get extensions
    var exts = match && exports.extensions[match[1].toLowerCase()]
  
    if (!exts || !exts.length) {
      return false
    }
  
    return exts[0]
  }
docs: Get the default extension for a MIME type.
  
  @param {string} type
  @return {boolean|string}