private com.google.protobuf.SingleFieldBuilderV3<
            com.google.cloud.visionai.v1.Corpus,
            com.google.cloud.visionai.v1.Corpus.Builder,
            com.google.cloud.visionai.v1.CorpusOrBuilder>
        getCorpusFieldBuilder() {
      if (corpusBuilder_ == null) {
        corpusBuilder_ =
            new com.google.protobuf.SingleFieldBuilderV3<
                com.google.cloud.visionai.v1.Corpus,
                com.google.cloud.visionai.v1.Corpus.Builder,
                com.google.cloud.visionai.v1.CorpusOrBuilder>(
                getCorpus(), getParentForChildren(), isClean());
        corpus_ = null;
      }
      return corpusBuilder_;
    }
<pre>
Required. The corpus which replaces the resource on the server.
</pre>

<code>.google.cloud.visionai.v1.Corpus corpus = 1 [(.google.api.field_behavior) = REQUIRED];
</code>
java-visionai/proto-google-cloud-visionai-v1/src/main/java/com/google/cloud/visionai/v1/UpdateCorpusRequest.java