public Builder mergeFrom(com.google.cloud.texttospeech.v1beta1.CustomPronunciations other) {
      if (other == com.google.cloud.texttospeech.v1beta1.CustomPronunciations.getDefaultInstance())
        return this;
      if (pronunciationsBuilder_ == null) {
        if (!other.pronunciations_.isEmpty()) {
          if (pronunciations_.isEmpty()) {
            pronunciations_ = other.pronunciations_;
            bitField0_ = (bitField0_ & ~0x00000001);
          } else {
            ensurePronunciationsIsMutable();
            pronunciations_.addAll(other.pronunciations_);
          }
          onChanged();
        }
      } else {
        if (!other.pronunciations_.isEmpty()) {
          if (pronunciationsBuilder_.isEmpty()) {
            pronunciationsBuilder_.dispose();
            pronunciationsBuilder_ = null;
            pronunciations_ = other.pronunciations_;
            bitField0_ = (bitField0_ & ~0x00000001);
            pronunciationsBuilder_ =
                com.google.protobuf.GeneratedMessageV3.alwaysUseFieldBuilders
                    ? getPronunciationsFieldBuilder()
                    : null;
          } else {
            pronunciationsBuilder_.addAllMessages(other.pronunciations_);
          }
        }
      }
      this.mergeUnknownFields(other.getUnknownFields());
      onChanged();
      return this;
    }
<pre>
A collection of pronunciation customizations.
</pre>

Protobuf type {@code google.cloud.texttospeech.v1beta1.CustomPronunciations}
java-texttospeech/proto-google-cloud-texttospeech-v1beta1/src/main/java/com/google/cloud/texttospeech/v1beta1/CustomPronunciations.java