NOT does *not* implement compare(); the method body in EntityComparisonOperator will throw UnsupportedOperationException. In addition, the generated sql with be 'foo NOT bar', which I don't think is valid.
In actuality, NOT should be a Join operator; however, the condition system doesn't support a Join operator that takes a single expression. I've grepped all java source files, and nothing uses the NOT operator. I haven't searched any other supplementary code files. Should I work at trying to fix this, or should NOT just be removed, as it's never actually worked at all.
