code: def concatenate_slh(self, other):
          
          selfS = self.S
          otherS = other.S
          new_S = block_matrix(
                  selfS, zerosm((selfS.shape[0], otherS.shape[1]), dtype=int),
                  zerosm((otherS.shape[0], selfS.shape[1]), dtype=int), otherS)
          new_L = vstackm((self.L, other.L))
          new_H = self.H + other.H
  
          return SLH(new_S, new_L, new_H)
docs: Concatenation with another :class:`SLH` object