private synchronized Object getFromMetal( String key, Locale l ) {
			if( metalDefaults == null ) {
				metalDefaults = new MetalLookAndFeel() {
					// avoid unnecessary initialization
					@Override protected void initClassDefaults( UIDefaults table ) {}
					@Override protected void initSystemColorDefaults( UIDefaults table ) {}
				}.getDefaults();

				// empty not needed defaults (to save memory) because we're only interested
				// in resource bundle strings, which are stored in another internal map
				metalDefaults.clear();
			}

			return metalDefaults.get( key, l );
		}
Sets the preferred font family to be used for monospaced fonts.
<p>
<strong>Note</strong>: This must be invoked <strong>before</strong> setting
the application look and feel.

@since 3
flatlaf-core/src/main/java/com/formdev/flatlaf/FlatLaf.java