code: def maximum_vline_bundle(self, x0, y0, y1):
          
  
          y_range = range(y1, y0 - 1, -1) if y0 < y1 else range(y1, y0 + 1)
          vlines = [[(x0, y, 1, k) for y in y_range] for k in range(self.L)]
          return list(filter(self._contains_line, vlines))
docs: Compute a maximum set of vertical lines in the unit cells ``(x0,y)``
          for :math:`y0 \leq y \leq y1`.
  
          INPUTS:
              y0,x0,x1: int
  
          OUTPUT:
              list of lists of qubits