public boolean hasSsml() {
    return inputSourceCase_ == 2;
  }
<pre>
The SSML document to be synthesized. The SSML document must be valid
and well-formed. Otherwise the RPC will fail and return
[google.rpc.Code.INVALID_ARGUMENT][google.rpc.Code.INVALID_ARGUMENT]. For
more information, see
[SSML](https://cloud.google.com/text-to-speech/docs/ssml).
</pre>

<code>string ssml = 2;</code>

@return Whether the ssml field is set.
java-texttospeech/proto-google-cloud-texttospeech-v1beta1/src/main/java/com/google/cloud/texttospeech/v1beta1/SynthesisInput.java