# Problem
The `no-iterator` rule is not being triggered by the `RuleTester`, even with invalid code.

# Attempts
1. I wrote a standard test with a valid and invalid case, but the invalid case was not flagged.
2. I corrected the error message, but the test still failed.
3. I used a different syntax for the invalid case, but the issue persisted.

# Possible Solution
The issue may be related to the version of ESLint being used. It's possible that the `no-iterator` rule is deprecated or has been superseded by another rule in this version.