default T create(ExternalContext externalContext, JobContext jobContext, ContainerContext containerContext,
      TaskContext taskContext, ApplicationContainerContext applicationContainerContext) {
    return create(jobContext, containerContext, taskContext, applicationContainerContext);
  }
Creates an instance of the application-defined {@link ApplicationTaskContext}.
<p>
Applications should implement this to provide a context for task 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
@param taskContext framework-provided task context
@param applicationContainerContext application-defined container context; null if it was not provided
@return a new instance of the application-defined {@link ApplicationTaskContext}
samza-api/src/main/java/org/apache/samza/context/ApplicationTaskContextFactory.java