I believe that the requirement is being exercised but not say, directly called in the test.
What does "but not say" mean? Does it mean something like "though we can't say"?
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Sign up to join this communityIt is perhaps more meaningful if another comma is placed before "say".
I believe that the requirement is being exercised but not, say, directly called in the test.
This would mean there is a requirement, but it is not stated or asked for in the test itself.