protected final CustomConverter<?, ?> scanConvertors(final Method it) {
		final Converter convertor = it.getAnnotation(Converter.class);
		if (convertor != null) {
			if (null == convertor.value()) {
				throw new IllegalMappingException(
						"null is illegal convertor type");
			}
			final Set<Class<?>> interfaces = new HashSet<Class<?>>(
					Arrays.asList(convertor.value().getInterfaces()));
			if (!interfaces.contains(CustomConverter.class)) {
				throw new IllegalMappingException(convertor.value().getName()
						+ " should implement TypeConvertor");
			}
			try {
				return convertor.value().newInstance();
			} catch (InstantiationException e) {
				throw new IllegalMappingException(
						"Conveter must have public visibility and default public constructor",
						e);
			} catch (IllegalAccessException e) {
				throw new IllegalMappingException(
						"Conveter must have  public visibility and default public constructor",
						e);
			}
		}
		return null;
	}