WeChat.UserBlacklist.batch_unblacklist

You're seeing just the function batch_unblacklist, go back to WeChat.UserBlacklist module for more information.
Link to this function

batch_unblacklist(client, openid_list)

Specs

batch_unblacklist(WeChat.client(), WeChat.openid_list()) :: WeChat.response()

取消拉黑用户 - 官方文档