private com.google.protobuf.SingleFieldBuilderV3<
            com.google.cloud.vertexai.api.Content,
            com.google.cloud.vertexai.api.Content.Builder,
            com.google.cloud.vertexai.api.ContentOrBuilder>
        getContentFieldBuilder() {
      if (contentBuilder_ == null) {
        contentBuilder_ =
            new com.google.protobuf.SingleFieldBuilderV3<
                com.google.cloud.vertexai.api.Content,
                com.google.cloud.vertexai.api.Content.Builder,
                com.google.cloud.vertexai.api.ContentOrBuilder>(
                getContent(), getParentForChildren(), isClean());
        content_ = null;
      }
      return contentBuilder_;
    }
<pre>
Output only. Content parts of the candidate.
</pre>

<code>
.google.cloud.vertexai.v1.Content content = 2 [(.google.api.field_behavior) = OUTPUT_ONLY];
</code>
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/Candidate.java