code: def get_equivalent_kpoints(self, index):
          
          # if the kpoint has no label it can"t have a repetition along the band
          # structure line object
  
          if self.kpoints[index].label is None:
              return [index]
  
          list_index_kpoints = []
          for i in range(len(self.kpoints)):
              if self.kpoints[i].label == self.kpoints[index].label:
                  list_index_kpoints.append(i)
  
          return list_index_kpoints
docs: Returns the list of kpoint indices equivalent (meaning they are the
          same frac coords) to the given one.
  
          Args:
              index: the kpoint index
  
          Returns:
              a list of equivalent indices
  
          TODO: now it uses the label we might want to use coordinates instead
          (in case there was a mislabel)