public void setEngine(String engine) {
        this.engine = engine;
    }
<p>
Specifies the engine (<code>standard</code>, <code>neural</code>, <code>long-form</code>, or
<code>generative</code>) for Amazon Polly to use when processing input text for speech synthesis. Provide an
engine that is supported by the voice you select. If you don't provide an engine, the standard engine is selected
by default. If a chosen voice isn't supported by the standard engine, this will result in an error. For
information on Amazon Polly voices and which voices are available for each engine, see <a
href="https://docs.aws.amazon.com/polly/latest/dg/voicelist.html">Available Voices</a>.
</p>
<p>
Type: String
</p>
<p>
Valid Values: <code>standard</code> | <code>neural</code> | <code>long-form</code> | <code>generative</code>
</p>
<p>
Required: Yes
</p>

@param engine
       Specifies the engine (<code>standard</code>, <code>neural</code>, <code>long-form</code>, or
       <code>generative</code>) for Amazon Polly to use when processing input text for speech synthesis. Provide
       an engine that is supported by the voice you select. If you don't provide an engine, the standard engine
       is selected by default. If a chosen voice isn't supported by the standard engine, this will result in an
       error. For information on Amazon Polly voices and which voices are available for each engine, see <a
       href="https://docs.aws.amazon.com/polly/latest/dg/voicelist.html">Available Voices</a>.</p>
       <p>
       Type: String
       </p>
       <p>
       Valid Values: <code>standard</code> | <code>neural</code> | <code>long-form</code> |
       <code>generative</code>
       </p>
       <p>
       Required: Yes
@see Engine
aws-java-sdk-polly/src/main/java/com/amazonaws/services/polly/model/SynthesizeSpeechRequest.java