@java.lang.Override
  public void writeTo(com.google.protobuf.CodedOutputStream output) throws java.io.IOException {
    if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(networkCode_)) {
      com.google.protobuf.GeneratedMessageV3.writeString(output, 1, networkCode_);
    }
    if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(assetKey_)) {
      com.google.protobuf.GeneratedMessageV3.writeString(output, 2, assetKey_);
    }
    if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(customAssetKey_)) {
      com.google.protobuf.GeneratedMessageV3.writeString(output, 3, customAssetKey_);
    }
    getUnknownFields().writeTo(output);
  }
<pre>
Output only. The custom asset key identifier generated for the live config.
</pre>

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

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