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# EvaluationError.duplicateMetricName(name:)

Two evaluators — or a single evaluator returning multiple metrics — produced a metric
with the same name for the same sample.

```
case duplicateMetricName(name: String)
```

## Parameters

`name`

The metric name that was produced more than once.

## Discussion

Metric names double as DataFrame column names, so a repeated name would otherwise
silently overwrite the first metric’s value instead of failing loudly.

---

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