Cd_graph {

	void checkDefinedClasses() {{

		HashSet classes = this.collectClasses();
		this.checkDefined( classes );

	}}

	HashSet collectClasses() bypassing Neighbors to Vertex {

		{{ HashSet collection = new HashSet(); }}

		before Vertex {{
			collection.add( host.get_vertex_name() );
		}}

		after Cd_graph {{
			return_val = collection;
		}}

	}

	HashSet checkDefined( HashSet classes ) through Neighbors_wc to Vertex {

		before Vertex {{

			if ( classes.contains( host.get_vertex_name() ) ) {
			} else {
				System.out.println( "Warning: " + host.get_vertex_name() + " is not defined in class dictionary." );
			}

		}}

	}

}