@java.lang.Override
  public java.lang.String getVoiceCloningKey() {
    java.lang.Object ref = voiceCloningKey_;
    if (ref instanceof java.lang.String) {
      return (java.lang.String) ref;
    } else {
      com.google.protobuf.ByteString bs = (com.google.protobuf.ByteString) ref;
      java.lang.String s = bs.toStringUtf8();
      voiceCloningKey_ = s;
      return s;
    }
  }
<pre>
Required. Created by GenerateVoiceCloningKey.
</pre>

<code>string voice_cloning_key = 1 [(.google.api.field_behavior) = REQUIRED];</code>

@return The voiceCloningKey.
java-texttospeech/proto-google-cloud-texttospeech-v1beta1/src/main/java/com/google/cloud/texttospeech/v1beta1/VoiceCloneParams.java