jrapidoc-rest-plugin/src/main/java/org/jboss/resteasy/util/Types.java
public static Type[] findParameterizedTypes(Class<?> root, Class<?> searchedFor) {
        if (searchedFor.isInterface()) {
            return findInterfaceParameterizedTypes(root, null, searchedFor);
        }
        return findClassParameterizedTypes(root, null, searchedFor);
    }
public static Type[] findParameterizedTypes(Class<?> root, Class<?> searchedFor) {
        if (searchedFor.isInterface()) {
            return findInterfaceParameterizedTypes(root, null, searchedFor);
        }
        return findClassParameterizedTypes(root, null, searchedFor);
    }
Search for the given interface or class within the root's class/interface
hierarchy. If the searched for class/interface is a generic return an
array of real types that fill it out.

@param root
@param searchedFor
@return