docs: def is_connected(T, directed=True):
      r"""Check connectivity of the transition matrix.
  
      Return true, if the input matrix is completely connected,
      effectively checking if the number of connected components equals one.
  
      Parameters
      ----------
      T : scipy.sparse matrix
          Transition matrix
      directed : bool, optional
         Whether to compute connected components for a directed  or
         undirected graph. Default is True.
  
      Returns
      -------
      connected : boolean, returning true only if T is connected.
  
  
      """
      nc = connected_components(T, directed=directed, connection='strong', \
                                return_labels=False)
      return nc == 1