code: def file_update(self, quick_key, filename=None, description=None,
                      mtime=None, privacy=None):
          
          return self.request('file/update', QueryParams({
              'quick_key': quick_key,
              'filename': filename,
              'description': description,
              'mtime': mtime,
              'privacy': privacy
          }))
docs: file/update
  
          http://www.mediafire.com/developers/core_api/1.3/file/#update