code: public static void applyOverlays(
  		Configuration configuration, ContainerSpecification containerSpec) throws IOException {
  
  		// create the overlays that will produce the specification
  		CompositeContainerOverlay overlay = new CompositeContainerOverlay(
  			FlinkDistributionOverlay.newBuilder().fromEnvironment(configuration).build(),
  			HadoopConfOverlay.newBuilder().fromEnvironment(configuration).build(),
  			HadoopUserOverlay.newBuilder().fromEnvironment(configuration).build(),
  			KeytabOverlay.newBuilder().fromEnvironment(configuration).build(),
  			Krb5ConfOverlay.newBuilder().fromEnvironment(configuration).build(),
  			SSLStoreOverlay.newBuilder().fromEnvironment(configuration).build()
  		);
  
  		// apply the overlays
  		overlay.configure(containerSpec);
  	}
docs: Generate a container specification as a TaskManager template.
  
  <p>This code is extremely Mesos-specific and registers all the artifacts that the TaskManager
  needs (such as JAR file, config file, ...) and all environment variables into a container specification.
  The Mesos fetcher then ensures that those artifacts will be copied into the task's sandbox directory.
  A lightweight HTTP server serves the artifacts to the fetcher.