I think I'll let Mike chime in.
If they come to Canada, the committee can then seek to enforce the summons. The committee maintains the power, when the person arrives on Canadian soil, to seek to enforce it. Whether or not they accept the invitation of the committee would certainly be something they would consider if they come to Canada frequently.
Again, as Mike said, we have no power to force them. I believe we had Mr. Zuckerberg when we did that the last time, and we had no power to force it, but if they ever do come to Canada, we can then actually attempt to enforce it. Certainly, given that we have a Canadian on the list, we know that she is required to come, and we'll see how the others comport themselves. Hopefully, they'll be co-operative—