Theme.AppCompat is supplied by the Android Support Library

When I started digging into the styles.xml file of our React Native app I found XML like this:

<resources>
    <style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
        <item name="android:textColor">#000</item>

I understand that the parent attribute there means inherit the styles from the theme "Theme.AppCompat.Light.NoActionBar", I was searching the web where this theme was defined, until I found it while reading the android docs there I found the answer:

a theme such as Theme.AppCompat that's supplied by the Android Support Library

So it ships with android and since this is not open source (I think) I didn't find it. At least I know now where it comes from ;). I also found the answer to what the Android Support Library is.