protected Properties getAdditionalDefaults() {
		if( globalExtraDefaults == null && extraDefaults == null )
			return null;

		Properties properties = new Properties();
		if( globalExtraDefaults != null )
			properties.putAll( globalExtraDefaults );
		if( extraDefaults != null )
			properties.putAll( extraDefaults );
		return properties;
	}
Initialize Aqua LaF on macOS, which is required for using Mac screen menubar.
(at least on Java 8, since 9 it seems to work without it)
<p>
This loads the native library "osxui" and initializes JRSUI.
Because both are not unloaded/uninitialized, Aqua LaF is initialized only once.
flatlaf-core/src/main/java/com/formdev/flatlaf/FlatLaf.java