code: def omitted_jco(self):
          
          if self.__omitted_jco is None:
              self.log("loading omitted_jco")
              self.__load_omitted_jco()
              self.log("loading omitted_jco")
          return self.__omitted_jco
docs: get the omitted jco
  
          Returns
          -------
          omitted_jco : pyemu.Jco
  
          Note
          ----
          returns a reference
          
          if ErrorVariance.__omitted_jco is None,
          then dynamically load the attribute before returning