I can give you a general answer. In our opinion, this is similar to the Constitution, in that there would be a power to declare a work or undertaking to be in the national interest. I am going to give you an example, but I am not saying that is the case. For example, if a company were generating power for the entire country—and this is a totally fictitious example I'm giving you—it would be possible to declare that this was an undertaking for the general advantage of the country—and therefore national in nature.
I'm not aware of anything having been declared to come under that category. There is transportation, for example, but that is normally covered more specifically in the Constitution.