private com.google.protobuf.SingleFieldBuilderV3<
            com.google.cloud.visionai.v1.Collection,
            com.google.cloud.visionai.v1.Collection.Builder,
            com.google.cloud.visionai.v1.CollectionOrBuilder>
        getCollectionFieldBuilder() {
      if (collectionBuilder_ == null) {
        collectionBuilder_ =
            new com.google.protobuf.SingleFieldBuilderV3<
                com.google.cloud.visionai.v1.Collection,
                com.google.cloud.visionai.v1.Collection.Builder,
                com.google.cloud.visionai.v1.CollectionOrBuilder>(
                getCollection(), getParentForChildren(), isClean());
        collection_ = null;
      }
      return collectionBuilder_;
    }
<pre>
Required. The collection resource to be created.
</pre>

<code>
.google.cloud.visionai.v1.Collection collection = 2 [(.google.api.field_behavior) = REQUIRED];
</code>
java-visionai/proto-google-cloud-visionai-v1/src/main/java/com/google/cloud/visionai/v1/CreateCollectionRequest.java