code: function load(uri, options) {
    var loader = this;
    return loader.sanitize(uri, options)
      .then(function(opt) {
        var url = opt.href;
        return opt.localFile
          ? loader.file(url)
          : loader.http(url, options);
      });
  }
docs: Load an external resource, typically either from the web or from the local
  filesystem. This function uses {@link sanitize} to first sanitize the uri,
  then calls either {@link http} (for web requests) or {@link file} (for
  filesystem loading).
  @param {string} uri - The resource indicator (e.g., URL or filename).
  @param {object} [options] - Optional loading options. These options will
  override any existing default options.
  @return {Promise} - A promise that resolves to the loaded content.