code: function createFolder($path)
      {
          Path::checkArgNonRoot("path", $path);
  
          $response = $this->doPost(
              $this->apiHost,
              "1/fileops/create_folder",
              array(
                  "root" => "auto",
                  "path" => $path,
              ));
  
          if ($response->statusCode === 403) return null;
          if ($response->statusCode !== 200) throw RequestUtil::unexpectedStatus($response);
  
          return RequestUtil::parseResponseJson($response->body);
      }
docs: Creates a folder.
  
  See <a href="https://www.dropbox.com/developers/core/docs#fileops-create-folder">/fileops/create_folder</a>.
  
  @param string $path
  The Dropbox path at which to create the folder (UTF-8).
  
  @return array|null
  If successful, you'll get back the
  <a href="https://www.dropbox.com/developers/core/docs#metadata-details">metadata object</a>
  for the newly-created folder.  If not successful, you'll get `null`.
  
  @throws Exception