public Builder addAllTurns(
        java.lang.Iterable<? extends com.google.cloud.texttospeech.v1.MultiSpeakerMarkup.Turn>
            values) {
      if (turnsBuilder_ == null) {
        ensureTurnsIsMutable();
        com.google.protobuf.AbstractMessageLite.Builder.addAll(values, turns_);
        onChanged();
      } else {
        turnsBuilder_.addAllMessages(values);
      }
      return this;
    }
<pre>
Required. Speaker turns.
</pre>

<code>
repeated .google.cloud.texttospeech.v1.MultiSpeakerMarkup.Turn turns = 1 [(.google.api.field_behavior) = REQUIRED];
</code>
java-texttospeech/proto-google-cloud-texttospeech-v1/src/main/java/com/google/cloud/texttospeech/v1/MultiSpeakerMarkup.java