code: private Method getMethod(Class visitorClass, Object argument) {
  		ClassVisitMethods visitMethods = (ClassVisitMethods) this.visitorClassVisitMethods
  				.get(visitorClass);
  		return visitMethods.getVisitMethod(argument != null ? argument
  				.getClass() : null);
  	}
docs: Determines the most appropriate visit method for the given visitor class
  and argument.