public java.lang.String getMetricName() {
      java.lang.Object ref = metricName_;
      if (!(ref instanceof java.lang.String)) {
        com.google.protobuf.ByteString bs = (com.google.protobuf.ByteString) ref;
        java.lang.String s = bs.toStringUtf8();
        metricName_ = s;
        return s;
      } else {
        return (java.lang.String) ref;
      }
    }
<pre>
Required. The resource metric name.
Supported metrics:

* For Online Prediction:
* `aiplatform.googleapis.com/prediction/online/accelerator/duty_cycle`
* `aiplatform.googleapis.com/prediction/online/cpu/utilization`
</pre>

<code>string metric_name = 1 [(.google.api.field_behavior) = REQUIRED];</code>

@return The metricName.
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/AutoscalingMetricSpec.java