public static String[] getAvailableFontFamilyNames() {
		String[] availableFontFamilyNames = GraphicsEnvironment.getLocalGraphicsEnvironment().getAvailableFontFamilyNames();
		if( !hasLoaders() )
			return availableFontFamilyNames;

		// append families that are not yet loaded
		ArrayList<String> result = new ArrayList<>( availableFontFamilyNames.length + loadersMap.size() );
		for( String name : availableFontFamilyNames )
			result.add( name );
		for( String name : loadersMap.keySet() ) {
			if( !result.contains( name ) )
				result.add( name );
		}

		return result.toArray( new String[result.size()] );
	}
Returns all font family names available in the graphics environment.
This invokes {@link GraphicsEnvironment#getAvailableFontFamilyNames()} and
appends families registered for lazy loading via {@link #registerFontFamilyLoader(String, Runnable)}
to the result.
flatlaf-core/src/main/java/com/formdev/flatlaf/util/FontUtils.java