code: def getlevel(self, threshold):
          
  
          # if it's not worth clustering, just return the data
          if len(self._input) <= 1:
              return self._input
  
          # initialize the cluster if not yet done
          if not self.__cluster_created:
              self.cluster()
  
          return self._data[0].getlevel(threshold)
docs: Returns all clusters with a maximum distance of *threshold* in between
          each other
  
          :param threshold: the maximum distance between clusters.
  
          See :py:meth:`~cluster.cluster.Cluster.getlevel`