Dumpsys output documentation? Hex number after package name, e.g. Package [com.android.fmradio] (2af5b15)

Running adb shell dumpsys | sed -n '/^Packages:/,/^[[:space:]]*$/p' yields a lot of information about installed packages. For example: Packages: Package [com.android.fmradio] (2af5b15): ... Following each package name com.android.fmradio there is a hex number, here 2af5b15, in brackets - what does this mean? Where do I find comprehensive documentation about dumpsys output? So far, I couldn't find anything on https://developer.android.com/tools/dumpsys about this, unfortunately.