public com.google.protobuf.ByteString getAssetIdBytes() {
      java.lang.Object ref = assetId_;
      if (ref instanceof String) {
        com.google.protobuf.ByteString b =
            com.google.protobuf.ByteString.copyFromUtf8((java.lang.String) ref);
        assetId_ = b;
        return b;
      } else {
        return (com.google.protobuf.ByteString) ref;
      }
    }
<pre>
Output only. The generated ID of the VodSession's source media.
</pre>

<code>string asset_id = 10 [(.google.api.field_behavior) = OUTPUT_ONLY];</code>

@return The bytes for assetId.
java-video-stitcher/proto-google-cloud-video-stitcher-v1/src/main/java/com/google/cloud/video/stitcher/v1/VodSession.java