docs: def del_sample(self, sample_id):
          """
          Method to remove a sample from the dataset.
  
          Parameters
          ----------
          sample_id : str
              sample id to be removed.
  
          Raises
          ------
          UserWarning
              If sample id to delete was not found in the dataset.
  
          """
          if sample_id not in self.__data:
              warnings.warn('Sample to delete not found in the dataset - nothing to do.')
          else:
              self.__data.pop(sample_id)
              self.__classes.pop(sample_id)
              self.__labels.pop(sample_id)
              print('{} removed.'.format(sample_id))