private com.google.protobuf.SingleFieldBuilderV3<
            com.google.cloud.vertexai.api.SpeculativeDecodingSpec.DraftModelSpeculation,
            com.google.cloud.vertexai.api.SpeculativeDecodingSpec.DraftModelSpeculation.Builder,
            com.google.cloud.vertexai.api.SpeculativeDecodingSpec.DraftModelSpeculationOrBuilder>
        getDraftModelSpeculationFieldBuilder() {
      if (draftModelSpeculationBuilder_ == null) {
        if (!(speculationCase_ == 2)) {
          speculation_ =
              com.google.cloud.vertexai.api.SpeculativeDecodingSpec.DraftModelSpeculation
                  .getDefaultInstance();
        }
        draftModelSpeculationBuilder_ =
            new com.google.protobuf.SingleFieldBuilderV3<
                com.google.cloud.vertexai.api.SpeculativeDecodingSpec.DraftModelSpeculation,
                com.google.cloud.vertexai.api.SpeculativeDecodingSpec.DraftModelSpeculation.Builder,
                com.google.cloud.vertexai.api.SpeculativeDecodingSpec
                    .DraftModelSpeculationOrBuilder>(
                (com.google.cloud.vertexai.api.SpeculativeDecodingSpec.DraftModelSpeculation)
                    speculation_,
                getParentForChildren(),
                isClean());
        speculation_ = null;
      }
      speculationCase_ = 2;
      onChanged();
      return draftModelSpeculationBuilder_;
    }
<pre>
draft model speculation.
</pre>

<code>
.google.cloud.vertexai.v1.SpeculativeDecodingSpec.DraftModelSpeculation draft_model_speculation = 2;
</code>
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/SpeculativeDecodingSpec.java