public void setDimensions(Map<DimensionId, String> dimensions) {
        this.dimensions = Map.copyOf(dimensions);
    }
Creates a new metric instance

@param name  The metric name. E.g 'documents'
@param value The numeric value
@param time  The timestamp of this metric in seconds
metrics-proxy/src/main/java/ai/vespa/metricsproxy/metric/Metric.java