docs: def get_metadata(self):
          """ Returns the metadata related to the current GMQLDataset. This function can be used only
          when a local dataset is loaded using the :meth:`~gmql.dataset.loaders.Loader.load_from_path` and no other
          operation has been called on the GMQLDataset.
  
          The metadata are returned in the form of a Pandas Dataframe having as index the sample ids and as columns
          the metadata attributes.
  
          :return: a Pandas Dataframe
          """
          if self.path_or_name is None:
              raise ValueError("You cannot explore the metadata of an intermediate query."
                               "You can get metadata only after a load_from_local or load_from_remote")
          if self.location == 'local':
              return self.__get_metadata_local()
          elif self.location == 'remote':
              return self.__get_metadata_remote()