question: private void compileDefaults ( Map < String , TreeMap < String , Object > > compiledDefaults , UIDefaults d ) { for ( Map . Entry < Object , Object > entry : d . entrySet ( ) ) { if ( entry . getKey ( ) instanceof String ) { String key = ( String ) entry . getKey ( ) ; String kp = parsePrefix ( key ) ; if ( kp == null ) continue ; TreeMap < String , Object > map = compiledDefaults . get ( kp ) ; if ( map == null ) { map = new TreeMap < String , Object > ( ) ; compiledDefaults . put ( kp , map ) ; } map . put ( key , entry . getValue ( ) ) ; } } }
target:  Iterates over all the keys in the specified UIDefaults and compiles those keys into the comiledDefaults data structure. It relies on parsing the "prefix" out of the key. If the key is not a String or is null then it is ignored. In all other cases a prefix is parsed out (even if that prefix is the empty String or is a "fake" prefix. That is, suppose you had a key Foo~~MySpecial.KeyThing~~. In this case this is not a SeaGlass formatted key, but we don't care, we treat it as if it is. This doesn't pose any harm, it will simply never be used).