code: def agent_list(self, deep_sorted=False):
          
          ag_list = []
          for ag_name in self._agent_order:
              ag_attr = getattr(self, ag_name)
              if isinstance(ag_attr, Concept) or ag_attr is None:
                  ag_list.append(ag_attr)
              elif isinstance(ag_attr, list):
                  if not all([isinstance(ag, Concept) for ag in ag_attr]):
                      raise TypeError("Expected all elements of list to be Agent "
                                      "and/or Concept, but got: %s"
                                      % {type(ag) for ag in ag_attr})
                  if deep_sorted:
                      ag_attr = sorted_agents(ag_attr)
                  ag_list.extend(ag_attr)
              else:
                  raise TypeError("Expected type Agent, Concept, or list, got "
                                  "type %s." % type(ag_attr))
          return ag_list
docs: Get the canonicallized agent list.