code: def _load_manifest_from_file(manifest, path):
      
      path = os.path.abspath(os.path.expanduser(path))
      if not os.path.exists(path):
          raise ManifestException("Manifest does not exist at {0}!".format(path))
      manifest.read(path)
      if not manifest.has_option('config', 'source'):
          manifest.set('config', 'source', str(path))
docs: load manifest from file