首页多个tab的形式，如果其中有一个fragment A是FlutterBoost的fragment，则如果从这个tab页面，跳转到FlutterBoostActivity B，则从B测滑回到首页Tab A后，快速再次测滑，则会连续调用两次首页的onBackPressed方法。

首页多个tab的形式，如果其中有一个fragment A是FlutterBoost的fragment，则如果从这个tab页面，跳转到FlutterBoostActivity B，则从B测滑回到首页Tab A后，快速再次测滑，则会连续调用两次首页的onBackPressed方法。
该问题导致原本首页需要两次测滑才能退出应用，现在只需要一次，就会退出；

Start by reproducing the reported sequence with a tab containing a FlutterBoost fragment: open FlutterBoostActivity B, swipe back to tab A, then quickly swipe again. Trace the home screen's onBackPressed handling and verify that the callback occurs once and that exiting the app still requires two swipes.

Written by the indexing model from the issue text.