Correct syntax for creating domain selection in the JAVA Api?

I am trying to follow the busbar tutorial using Comsol + Matlab.

To create a variable representing multiple boundaries to avoid redundancy the following code is given:

<code>
sel1 = model.selection.create('sel1');
sel1.set([2 3 4 5 6 7]);
sel1.name('Ti bolts');
</code>

Matlab returns the following error:

Error using busbar (line 54)
Java exception occurred:
Exception:
java.lang.IllegalArgumentException: Illegal input vector
(rethrown as com.comsol.util.exceptions.FlException)
Messages:
Illegal input vector

Line 54 refers to the second line of code.
Any one knows what the issue may be with the syntax if that's the problem?

Thank you,
Kayode