@Override
	public void afterDefaultsLoading( LookAndFeel laf, UIDefaults defaults ) {
		// TristateCheckBox
		defaults.put( "TristateCheckBox.icon", null );
		defaults.put( "TristateCheckBox.setMixed.clientProperty",   new Object[] { FlatClientProperties.SELECTED_STATE, FlatClientProperties.SELECTED_STATE_INDETERMINATE } );
		defaults.put( "TristateCheckBox.clearMixed.clientProperty", new Object[] { FlatClientProperties.SELECTED_STATE, null } );
	}
Finds JIDE Common Layer addon .properties file for the given LaF class
in the same package as this class.
flatlaf-jide-oss/src/main/java/com/formdev/flatlaf/jideoss/FlatJideOssDefaultsAddon.java