@java.lang.Override
    public Builder toBuilder() {
      return this == DEFAULT_INSTANCE ? new Builder() : new Builder().mergeFrom(this);
    }
<pre>
Aggregate method for the current data schema key.
</pre>

<code>
optional .google.cloud.visionai.v1.SchemaKeySortingStrategy.Option.AggregateMethod aggregate_method = 3;
</code>

@return The aggregateMethod.
java-visionai/proto-google-cloud-visionai-v1/src/main/java/com/google/cloud/visionai/v1/SchemaKeySortingStrategy.java