Function pop_back

include/behaviortree_cpp/contrib/json.hpp:13964–13972

@brief remove last reference token @sa https://json.nlohmann.me/api/json_pointer/pop_back/

    /// @brief remove last reference token
    /// @sa https://json.nlohmann.me/api/json_pointer/pop_back/
    void pop_back()
    {
        if (JSON_HEDLEY_UNLIKELY(empty()))
        {
            JSON_THROW(detail::out_of_range::create(405, "JSON pointer has no parent", nullptr));
        }

        reference_tokens.pop_back();
    }

    /// @brief return last reference token
    /// @sa https://json.nlohmann.me/api/json_pointer/back/