Return type:
         Module
update(modules)
  Update the "ModuleDict" with the key-value pairs from a mapping
  or an iterable, overwriting existing keys.

  Note:

    If "modules" is an "OrderedDict", a "ModuleDict", or an
    iterable of key-value pairs, the order of new elements in it
    is preserved.

  Parameters:
     **modules** (*iterable*) -- a mapping (dictionary) from
     string to "Module", or an iterable of key-value pairs of type
     (string, "Module")

values()
  Return an iterable of the ModuleDict values.

  Return type:
     *Iterable*[*Module*]
