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Not all SimpleMetrics are defined on all types. Types on which you can evaluate a metric mixin the Type 'MetricEvaluatable' (C3 Docs here: https://developer.c3.ai/docs/7.12.0/type/MetricEvaluatable)
This bestows the function 'listMetrics' (among others) to that type, so if you're unsure what kind of metrics are available for a given type, execute that function to get a list, for example:
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