code: def modules(self):
          
          defmodule = lib.EnvGetNextDefmodule(self._env, ffi.NULL)
  
          while defmodule != ffi.NULL:
              yield Module(self._env, defmodule)
  
              defmodule = lib.EnvGetNextDefmodule(self._env, defmodule)
docs: Iterates over the defined Modules.