WorkflowDefinition
    graph       (WorkflowGraph Int64 Int64)
    scope       WorkflowInstanceScope'

WorkflowInstance
    definition  WorkflowDefinition
    graph       (WorkflowGraph Int64 Int64)  -- FileId, UserId
    scope       (WorkflowInstanceScope Int64 Int64 Int64)  -- TermId, SchoolId, CourseId

WorkflowWorkflow
    instance    WorkflowInstance
    graph       (WorkflowGraph Int64 Int64)  -- FileId, UserId
    initiator   UserId Maybe
    payload     (WorkflowPayload Int64 Int64)  -- FileId, UserId
    currentNode WorkflowGraphNodeLabel Maybe