private com.google.protobuf.SingleFieldBuilderV3<
            com.google.cloud.vertexai.api.SpeculativeDecodingSpec,
            com.google.cloud.vertexai.api.SpeculativeDecodingSpec.Builder,
            com.google.cloud.vertexai.api.SpeculativeDecodingSpecOrBuilder>
        getSpeculativeDecodingSpecFieldBuilder() {
      if (speculativeDecodingSpecBuilder_ == null) {
        speculativeDecodingSpecBuilder_ =
            new com.google.protobuf.SingleFieldBuilderV3<
                com.google.cloud.vertexai.api.SpeculativeDecodingSpec,
                com.google.cloud.vertexai.api.SpeculativeDecodingSpec.Builder,
                com.google.cloud.vertexai.api.SpeculativeDecodingSpecOrBuilder>(
                getSpeculativeDecodingSpec(), getParentForChildren(), isClean());
        speculativeDecodingSpec_ = null;
      }
      return speculativeDecodingSpecBuilder_;
    }
<pre>
Optional. Spec for configuring speculative decoding.
</pre>

<code>
.google.cloud.vertexai.v1.SpeculativeDecodingSpec speculative_decoding_spec = 30 [(.google.api.field_behavior) = OPTIONAL];
</code>
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/DeployedModel.java