def load_installed_version(self):
        installed_packages = get_installed_pypackages()
        if self.package in installed_packages:
            self.version = "=={}".format(
                installed_packages[self.package].version)
def add_target_handle(self, layer):
        input_handle = layer.register_forward_hook(get_target_input)
        self.target_handle = input_handle