code: def _as_reference_point(self) -> np.ndarray:
          
          ref_val = []
          for fn, f in self._classification.items():
              if f[0] == "<":
                  ref_val.append(self._method.problem.ideal[fn])
              elif f[0] == "<>":
                  ref_val.append(self._method.problem.nadir[fn])
              else:
                  ref_val.append(f[1])
  
          return np.array(ref_val)
docs: Return classification information as reference point