public com.google.protobuf.ByteString getMimeTypeBytes() {
      java.lang.Object ref = mimeType_;
      if (ref instanceof String) {
        com.google.protobuf.ByteString b =
            com.google.protobuf.ByteString.copyFromUtf8((java.lang.String) ref);
        mimeType_ = b;
        return b;
      } else {
        return (com.google.protobuf.ByteString) ref;
      }
    }
<pre>
Optional. The format of the source text, for example, "text/html",
"text/plain". If left blank, the MIME type defaults to "text/html".
</pre>

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

@return The bytes for mimeType.
java-translate/proto-google-cloud-translate-v3beta1/src/main/java/com/google/cloud/translate/v3beta1/DetectLanguageRequest.java