public boolean isHasFullBorder() {
		return getClientPropertyBoolean( TABBED_PANE_HAS_FULL_BORDER, "TabbedPane.hasFullBorder" );
	}
Returns whether a full border is painted around a tabbed pane.
flatlaf-extras/src/main/java/com/formdev/flatlaf/extras/components/FlatTabbedPane.java