think\Process::setEnv PHP Method

    public function setEnv(array $env)
    {
        $env = array_filter($env, function ($value) {
            return !is_array($value);
        });
        $this->env = [];
        foreach ($env as $key => $value) {
            $this->env[(string) $key] = (string) $value;
        }
        return $this;
    }