private com.google.protobuf.SingleFieldBuilderV3<
            com.google.cloud.texttospeech.v1.StreamingSynthesizeConfig,
            com.google.cloud.texttospeech.v1.StreamingSynthesizeConfig.Builder,
            com.google.cloud.texttospeech.v1.StreamingSynthesizeConfigOrBuilder>
        getStreamingConfigFieldBuilder() {
      if (streamingConfigBuilder_ == null) {
        if (!(streamingRequestCase_ == 1)) {
          streamingRequest_ =
              com.google.cloud.texttospeech.v1.StreamingSynthesizeConfig.getDefaultInstance();
        }
        streamingConfigBuilder_ =
            new com.google.protobuf.SingleFieldBuilderV3<
                com.google.cloud.texttospeech.v1.StreamingSynthesizeConfig,
                com.google.cloud.texttospeech.v1.StreamingSynthesizeConfig.Builder,
                com.google.cloud.texttospeech.v1.StreamingSynthesizeConfigOrBuilder>(
                (com.google.cloud.texttospeech.v1.StreamingSynthesizeConfig) streamingRequest_,
                getParentForChildren(),
                isClean());
        streamingRequest_ = null;
      }
      streamingRequestCase_ = 1;
      onChanged();
      return streamingConfigBuilder_;
    }
<pre>
StreamingSynthesizeConfig to be used in this streaming attempt. Only
specified in the first message sent in a `StreamingSynthesize` call.
</pre>

<code>.google.cloud.texttospeech.v1.StreamingSynthesizeConfig streaming_config = 1;</code>
java-texttospeech/proto-google-cloud-texttospeech-v1/src/main/java/com/google/cloud/texttospeech/v1/StreamingSynthesizeRequest.java