出于某种我无法理解的原因，我的（研发）公司正在阻止 sdk 安装。如果我手动访问 sdk 下载链接，我会得到
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You tried to visit:http://dl.bintray.com/groovy/maven/apache-groovy-sdk-2.4.12.zip
因此我从家里下载然后尝试使用SDKMAN本地安装，但无论我尝试什么都失败了。
以下详细信息仅显示了我尝试过的方法，可以跳过：
$ sdk install groovy ~/Downloads/apache-groovy-sdk-2.4.12.zip
==== INTERNET NOT REACHABLE! ===================================================
Some functionality is disabled or only partially available.
If this persists, please enable the offline mode:
$ sdk offline
================================================================================
Stop! groovy /Users/xxx/Downloads/apache-groovy-sdk-2.4.12.zip is not available while offline.
$ sdk install groovy 2.4.12 ~/Downloads/groovy-2.4.12
==== INTERNET NOT REACHABLE! ===================================================
Some functionality is disabled or only partially available.
If this persists, please enable the offline mode:
$ sdk offline
================================================================================
Stop! groovy 2.4.12 is not available while offline.
$ sdk offline
Offline mode enabled.
$ sdk install groovy 2.4.12 ~/Downloads/apache-groovy-sdk-2.4.12
Stop! groovy 2.4.12 is not available while offline.
$ sdk install groovy ~/Downloads/apache-groovy-sdk-2.4.12.zip
Stop! groovy /Users/xxx/Downloads/apache-groovy-sdk-2.4.12.zip is not available while offline.
$ sdk install groovy ~/Downloads/apache-groovy-sdk-2.4.12
Stop! groovy /Users/xxx/Downloads/apache-groovy-sdk-2.4.12 is not available while offline.
我确定 zip 文件在那里，并让 UTSL 通过它自己的检查来验证：
[[ -n /Users/xxx/Downloads/apache-groovy-sdk-2.4.12.zip ]]
$ echo $?
0
那么，如何利用我下载的 .zip 并使用 SDKMAN 进行本地安装呢？