New Creates a new graph.

MainExecPhase indicates the main execution phase of the graph (normal running).

StateCommitted : the graph has been committed and can now terminate and can accept changes.

StateCompleted : No more events/data.

StateInitial : The graph has been created but not yet committed, can accept changes.

StateTerminating : No more regular stage executions.

TerminationExecPhase when termination hooks are running.

CompletionGraph describes the graph itself.

CompletionStage is a node in Graph, this implements StageDependency.

RawDependency - is a trivial StageDependency that implements a StageDependency from a completion result.

CompletionEventListener is a callback interface to receive notifications about stage triggers and graph events.

StageDependency is an abstract dependency of another stage - this may either be another stage (see CompletionStage) or a raw dependency (RawDependency).

ExecutionPhase tags stages into when in the graph they occur - stages may depend on other stages within a phase but not across two phases.

ExecutionStrategy defines how the node should behave when it is triggered (optionally calling the attached node closure and how the arguments to the closure are defined) different strategies can be applied when the stage completes successfully or exceptionally.

ResultHandlingStrategy defines how the result value of the stage is derived following execution of the stage if the result completes the node then implementations should signal to the graph that the node is complete (via graph.listener) this operation may moodify the graph (e.g.

State describes the lifecycle state of graph.

TriggerStrategy defines when a stage becomes active , and what the incoming status of the trigger is (success or fail) each type may or may not depend on the incoming dependencies of the node.