From the utPLSQL documentation:

> Validation of the code under test (the tested logic of procedure/function etc.) is performed by comparing the actual data against the expected data. utPLSQL uses a combination of expectation and matcher to perform the check on the data.

Some validations are written in the form of `ut.expect(actual_value).matcher(expected_value)`. This rules checks if the `actual_value` and the `expected_value` are the same thing. Example:

    ...
    begin
      v_expected := '2345';
      v_actual := betwnstr('1234567', 2, 5);
      ut.expect(v_actual).to_equal(v_actual); -- This expectation is wrong, it's always true
    end;