public void addMetric(MetricName metricName, MetricValueProvider<?> metricValueProvider) {
        addMetric(metricName, null, metricValueProvider);
    }
Add a metric to monitor an object that implements MetricValueProvider. This metric won't be associated with any
sensor. This is a way to expose existing values as metrics. User is expected to add any additional
synchronization to update and access metric values, if required.

@param metricName The name of the metric
@param metricValueProvider The metric value provider associated with this metric
clients/src/main/java/org/apache/kafka/common/metrics/Metrics.java