code: def largestNativeClique(self, max_chain_length=None):
          
          bigclique = []
          bestscore = None
          if max_chain_length is None:
              wmax = min(self.M, self.N)
          else:
              wmax = max_chain_length - 1
  
          for w in range(wmax + 1):
              score, clique = self.nativeCliqueEmbed(w)
              if bestscore is None or score > bestscore:
                  bigclique = clique
                  bestscore = score
          return bestscore, bigclique
docs: Returns the largest native clique embedding we can find on the
          processor, with the shortest chainlength possible (for that
          clique size).
  
          OUTPUT:
              score: the score for the returned clique (just ``len(clique)``
              in the class :class:`eden_processor`; may differ in subclasses)
  
              clique: a list containing lists of qubits, each associated
              to a chain.  These lists of qubits are carefully
              arranged so that
  
               >>> [zip(chain,chain[1:]) for chain in clique]
  
              is a list of valid couplers.
  
          CAVEAT: we assume that the only failed couplers connected to working
          qubits are between two cells.  Any pair of working qubits on opposite
          sides of the same unit cell are assumed to be connected by working
          couplers.