code: function getRevisions($path, $limit = null)
      {
          Path::checkArgNonRoot("path", $path);
          Checker::argIntPositiveOrNull("limit", $limit);
  
          $response = $this->doGet(
              $this->apiHost,
              $this->appendFilePath("1/revisions", $path),
              array("rev_limit" => $limit));
  
          if ($response->statusCode === 406) return null;
          if ($response->statusCode !== 200) throw RequestUtil::unexpectedStatus($response);
  
          return RequestUtil::parseResponseJson($response->body);
      }
docs: Gets the metadata for all the file revisions (up to a limit) for a given path.
  
  See <a href="https://www.dropbox.com/developers/core/docs#revisions">/revisions</a>.
  
  @param string path
  The Dropbox path that you want file revision metadata for (UTF-8).
  
  @param int|null limit
  The maximum number of revisions to return.
  
  @return array|null
  A list of <a href="https://www.dropbox.com/developers/core/docs#metadata-details>metadata
  objects</a>, one for each file revision.  The later revisions appear first in the list.
  If `null`, then there were too many revisions at that path.
  
  @throws Exception