@Override
		public V put( K key, V value )
			throws IllegalArgumentException
		{
			V oldValue = super.put( key, value );
			if( oldValue != null )
				throw new IllegalArgumentException( "duplicate key '" + key + "'" );
			return oldValue;
		}
Search for all fields annotated with {@link Styleable} and add them to the given map.
The key is the name of the field and the value the type of the field.
flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatStylingSupport.java