private E newInstance(PathMetadata pm) throws NoSuchMethodException,
        InstantiationException, IllegalAccessException,
        InvocationTargetException {
        if (constructor == null) {
            if (Constants.isTyped(queryType)) {
                constructor = queryType.getDeclaredConstructor(Class.class, PathMetadata.class);
            } else {
                constructor = queryType.getDeclaredConstructor(PathMetadata.class);
            }
            constructor.setAccessible(true);
        }
        if (Constants.isTyped(queryType)) {
            return constructor.newInstance(getValueType(), pm);
        } else {
            return constructor.newInstance(pm);
        }
    }
Get the value type

@return value type
querydsl-core/src/main/java/com/querydsl/core/types/dsl/MapPath.java