def instances(self):
ist = lib.EnvGetNextInstanceInClass(self._env, self._cls, ffi.NULL)<EOL>while ist != ffi.NULL:<EOL><INDENT>yield Instance(self._env, ist)<EOL>ist = lib.EnvGetNextInstanceInClass(self._env, self._cls, ist)<EOL><DEDENT>
Iterate over the instances of the class.