something fishy about Cody use of regexp?

I am playing around with the Cody problems...

The following function seems to do precisely what I want it to do when I run it locally (i.e., remove leading and trailing spaces, where space is only ASCII char 32), yet when I submit it to Cody, it fails each and every test case.

There seems to be a big difference between what is happening locally and what is happening within the Cody judge. Any ideas?

function b = removeSpaces(a)
  ca = regexp(a, '^ *([^ ].*[^ ]) *', 'tokens');
  b = ca{1};
end