Inserts an Android.OS.BinderConsts value into the mapping of this Bundle, replacing any existing value for the given key. Either key or value may be null.

You should be very careful when using this function. In many places where Bundles are used (such as inside of Intent objects), the Bundle can live longer inside of another process than the process that had originally created it. In that case, the IBinder you supply here will become invalid when your process goes away, and no longer usable, even if a new process is created for you later on.

[Android Documentation]