How to use the @aws-cdk/cx-api.ASSET_RESOURCE_METADATA_PATH_KEY function in @aws-cdk/cx-api

public addResourceMetadata(resource: cdk.CfnResource, resourceProperty: string) {
    if (!this.node.tryGetContext(cxapi.ASSET_RESOURCE_METADATA_ENABLED_CONTEXT)) {
      return; // not enabled
    }

    // tell tools such as SAM CLI that the "Code" property of this resource
    // points to a local path in order to enable local invocation of this function.
    resource.cfnOptions.metadata = resource.cfnOptions.metadata || { };
    resource.cfnOptions.metadata[cxapi.ASSET_RESOURCE_METADATA_PATH_KEY] = this.assetPath;
    resource.cfnOptions.metadata[cxapi.ASSET_RESOURCE_METADATA_PROPERTY_KEY] = resourceProperty;
  }