API changes

/**
 * Defines a custom action in the Workflow.
 */
public interface CustomAction extends ProgramLifecycle<CustomActionContext> {

  /**
   * Configure a custom Workflow action.
   */
  void configure(CustomActionConfigurer configurer);

  /**
   * @throws Exception
   */
  void run() throws Exception;
}

/**
 * Context used by action running in the Workflow.
 */
public interface CustomActionContext extends RuntimeContext, Transactional, PluginContext {

  /**
   * Return the specification of the Workflow that started this action
   */
  WorkflowSpecification getWorkflowSpecification();

  /**
   * Return the specification of the Action.
   */
   WorkflowActionSpecification getSpecification();

  /**
   * Return the logical start time of the Workflow
   */
  long getLogicalStartTime();

  /**
   * @return a {@link WorkflowToken}
   */
  WorkflowToken getToken();

  /**
   * Return true if the execution of the action is successful, false otherwise. This method can be
   * used from {@link AbstractCustomAction#destroy} to determine the status of the
   * {@link CustomAction}.
   */
  @Beta
  boolean isSuccessful();
}

public abstract class AbstractCustomAction implements CustomAction {
	private CustomActionContext context;
 
	@Override
	public void initialize(CustomActionContext context) throws Exception {
  		this.context = context;
	}
 
	protected final CustomActionContext getContext() {
  		return context;
	}
}

// Adds a CustomAction to the Workflow.
void addAction(CustomAction customAction);