code: def parameter_names_flat(self, include_fixed=False):
          
          name_list = []
          for p in self.flattened_parameters:
              name = p.hierarchy_name()
              if p.size > 1:
                  name_list.extend(["{}[{!s}]".format(name, i) for i in p._indices()])
              else:
                  name_list.append(name)
          name_list = np.array(name_list)
  
          if not include_fixed and self._has_fixes():
              return name_list[self._fixes_]
          return name_list
docs: Return the flattened parameter names for all subsequent parameters
          of this parameter. We do not include the name for self here!
  
          If you want the names for fixed parameters as well in this list,
          set include_fixed to True.
              if not hasattr(obj, 'cache'):
                  obj.cache = FunctionCacher()
          :param bool include_fixed: whether to include fixed names here.