public Builder setTargetLanguageCode(java.lang.String value) {
        if (value == null) {
          throw new NullPointerException();
        }
        targetLanguageCode_ = value;
        bitField0_ |= 0x00000004;
        onChanged();
        return this;
      }
<pre>
Target language code.
</pre>

<code>string target_language_code = 3;</code>

@param value The targetLanguageCode to set.
@return This builder for chaining.
java-translate/proto-google-cloud-translate-v3/src/main/java/com/google/cloud/translate/v3/AdaptiveMtTranslateRequest.java