default T create(ExternalContext externalContext, JobContext jobContext, ContainerContext containerContext) {
    return create(jobContext, containerContext);
  }
Creates an instance of the application-defined {@link ApplicationContainerContext}.
<p>
Applications should implement this to provide a context for container initialization.

@param externalContext external context provided for the application; null if it was not provided
@param jobContext framework-provided job context
@param containerContext framework-provided container context
@return a new instance of the application-defined {@link ApplicationContainerContext}
samza-api/src/main/java/org/apache/samza/context/ApplicationContainerContextFactory.java