def modules(self):
        """Iterates over the defined Modules."""
        defmodule = lib.EnvGetNextDefmodule(self._env, ffi.NULL)

        while defmodule != ffi.NULL:
            yield Module(self._env, defmodule)

            defmodule = lib.EnvGetNextDefmodule(self._env, defmodule)
Iterates over the defined Modules.