public Builder setInput(
        com.google.cloud.texttospeech.v1beta1.StreamingSynthesisInput.Builder builderForValue) {
      if (inputBuilder_ == null) {
        streamingRequest_ = builderForValue.build();
        onChanged();
      } else {
        inputBuilder_.setMessage(builderForValue.build());
      }
      streamingRequestCase_ = 2;
      return this;
    }
<pre>
Input to synthesize. Specified in all messages but the first in a
`StreamingSynthesize` call.
</pre>

<code>.google.cloud.texttospeech.v1beta1.StreamingSynthesisInput input = 2;</code>
java-texttospeech/proto-google-cloud-texttospeech-v1beta1/src/main/java/com/google/cloud/texttospeech/v1beta1/StreamingSynthesizeRequest.java