public Builder setLanguageCodeBytes(com.google.protobuf.ByteString value) {
      if (value == null) {
        throw new NullPointerException();
      }
      checkByteStringIsUtf8(value);
      languageCode_ = value;
      bitField0_ |= 0x00000010;
      onChanged();
      return this;
    }
<pre>
Required. The language of the supplied audio as a
[BCP-47](https://www.rfc-editor.org/rfc/bcp/bcp47.txt) language tag.
Example: "en-US".
See [Language
Support](https://cloud.google.com/speech-to-text/docs/languages) for a list
of the currently supported language codes.
</pre>

<code>string language_code = 3 [(.google.api.field_behavior) = REQUIRED];</code>

@param value The bytes for languageCode to set.
@return This builder for chaining.
java-speech/proto-google-cloud-speech-v1/src/main/java/com/google/cloud/speech/v1/RecognitionConfig.java