docs: def download_apcor(self, uri):
          """
          Downloads apcor data.
  
          Args:
            uri: The URI of the apcor data file.
  
          Returns:
            apcor: ossos.downloads.core.ApcorData
          """
  
          local_file = os.path.basename(uri)
          if os.access(local_file, os.F_OK):
              fobj = open(local_file)
          else:
              fobj = storage.vofile(uri, view='data')
              fobj.seek(0)
          str = fobj.read()
          fobj.close()
          apcor_str = str
          return ApcorData.from_string(apcor_str)