without the PHP_EOL still outputs 302 ... so somehow it seems its' abject inability to follow the rules of constant or variable definition therefore cause it not be looked up in the variables table -- even though it somehow circumvented those rules to get itself added into that table.
Is there are rational explanation? If so I'd like to hear it.
Whether anyone finds it remarkable, odd, or quirky -- its such an edge case, does it really matter? Probably not.
Anyhow, I'm still left wondering how the OPs class is using (or intending to use) these vars ...