def unpack_env_kwarg(self, kwargs) -> build.EnvironmentVariables:
    envlist = kwargs.get('env', EnvironmentVariablesHolder())
    if isinstance(envlist, EnvironmentVariablesHolder):
        env = envlist.held_object
    elif isinstance(envlist, dict):
        FeatureNew('environment dictionary', '0.52.0').use(self.subproject)
        env = EnvironmentVariablesHolder(envlist)
        env = env.held_object
    else:
        envlist = listify(envlist)
        env = EnvironmentVariablesHolder(envlist)
        env = env.held_object
    return env
def unpack_env_kwarg(self, kwargs) -> build.EnvironmentVariables:
    envlist = kwargs.get('env', EnvironmentVariablesHolder())
    if isinstance(envlist, EnvironmentVariablesHolder):
        env = envlist.held_object
    elif isinstance(envlist, dict):
        FeatureNew('environment dictionary', '0.52.0').use(self.subproject)
        env = EnvironmentVariablesHolder(envlist)
        env = env.held_object
    else:
        envlist = listify(envlist)
        env = EnvironmentVariablesHolder(envlist)
        env = env.held_object
    return env