callMakerMethods allways waits for a ClassNotFoundException

[jurgenvinju]

private static AbstractAST callMakerMethod(String sort, String cons, Object actuals[], Object keywordActuals[]) {
		try {
			String name = sort + '$' + cons;
			Constructor<?> constructor = astConstructors.get(name);

			if (constructor == null) {
				Class<?> clazz = null;

				try {
					clazz = classLoader.loadClass("org.rascalmpl.semantics.dynamic." + name);
				}
				catch (ClassNotFoundException e) {
					// it happens
				}

This must take some serious time since all these not found classes will build stacktraces.