code: def _clean_index(self):
          "Clean index values after loading."
          for idx_name, idx_def in self.index_defs.items():
              if idx_def['type'] == 'lazy':
                  self.build_index(idx_name)
          for index_name, values in self.indexes.items():
              for value in values:
                  if not isinstance(values[value], set):
                      values[value] = set(values[value]f _clean_index(self):
          "Clean index values after loading."
          for idx_name, idx_def in self.index_defs.items():
              if idx_def['type'] == 'lazy':
                  self.build_index(idx_name)
          for index_name, values in self.indexes.items():
              for value in values:
                  if not isinstance(values[value], set):
                      values[value] = set(values[value])
docs: Clean index values after loading.