@java.lang.Override
  public java.lang.String getDetectedLanguageCode() {
    java.lang.Object ref = detectedLanguageCode_;
    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();
      detectedLanguageCode_ = s;
      return s;
    }
  }
<pre>
The ISO-639 language code of source text in the initial request, detected
automatically, if no source language was passed within the initial
request. If the source language was passed, auto-detection of the language
does not occur and this field is empty.
</pre>

<code>string detected_language_code = 4;</code>

@return The detectedLanguageCode.
java-translate/proto-google-cloud-translate-v3/src/main/java/com/google/cloud/translate/v3/Translation.java